Organic electroluminescent device

ABSTRACT

An organic electroluminescent device of which emission life may be improved. The organic electroluminescent device includes an anode, an emission layer, and an anode-side hole transport layer provided between the anode and the emission layer and including an anode-side hole transport material. An electron accepting material is doped in the anode-side hole transport layer. An intermediate hole transport material layer is provided between the anode-side hole transport layer and the emission layer and includes an intermediate hole transport material, and an emission layer-side hole transport layer is provided between the intermediate hole transport material layer and the emission layer and adjacent to the emission layer. The emission layer-side hole transport layer includes an emission layer-side hole transport material represented by the following Formula 1.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/934,032, filed Nov. 5, 2015, which claims priority to and the benefitof Japanese Patent Application Nos. 2014-227110, filed on Nov. 7, 2014,and 2014-227118, filed on Nov. 7, 2014, the entire content of all ofwhich is incorporated herein by reference.

BACKGROUND

The present disclosure herein relates to an organic electroluminescentdevice.

Recently, the developments of organic electroluminescent (EL) displaysare being actively conducted. Also, the developments of organic ELdevices, which are self luminescent type emitting devices utilized inthe organic EL displays, are being actively conducted.

As the structure of the organic EL device, a stacked structure of, forexample, an anode, a hole transport layer, an emission layer, anelectron transport layer and a cathode in the stated order has beenutilized.

In such organic EL devices, holes and electrons injected from the anodeand the cathode recombine in the emission layer to generate excitons.The emission of light may be realized via the transition of thegenerated excitons to a ground state.

For example, in Patent Documents 1 to 4, technique on a hole transportmaterial or a hole transport layer in an organic EL device is disclosed.For example, a hole transport material utilized in a hole transportlayer is disclosed in Patent Document 1. In addition, technique ofadding an electron accepting material to a hole transport layer, etc.,is disclosed in Patent Document 2, and technique of forming a holetransport layer of a stacked structure utilizing a plurality of layersis disclosed in Patent Documents 3 and 4.

PATENT DOCUMENTS

-   (Patent Document 1) JP2002-241352 A-   (Patent Document 2) W02007-105906 A-   (Patent Document 3) KR10-2013-0007159 A-   (Patent Document 4) JP2011-187959 A

SUMMARY

However, according to the techniques disclosed in Patent Documents 1 to4, satisfactory values concerning the emission efficiency and theemission life of an organic EL device could not be obtained, and furtherimprovement thereof is required.

An aspect according to one or more embodiments of the presentdisclosure, considering the above-described limitation, is directedtoward a novel and improved organic EL device having improved emissionefficiency and emission life.

According to an embodiment of the present disclosure, an organic ELdevice includes an anode; an emission layer; an anode-side holetransport layer between the anode and the emission layer, the anode-sidehole transport layer including an anode-side hole transport material anddoped with an electron accepting material; an intermediate holetransport material layer between the anode-side hole transport layer andthe emission layer, the intermediate hole transport material layerincluding an intermediate hole transport material; and an emissionlayer-side hole transport layer between the intermediate hole transportmaterial layer and the emission layer, the emission layer-side holetransport layer including an emission layer-side hole transport materialrepresented by Formula 1.

In Formula 1, Y is O or S; R₁ to R₆ are each independently hydrogen,deuterium, a halogen atom, a substituted or unsubstituted alkyl grouphaving 1 to 15 carbon atoms, a substituted or unsubstituted silyl group,a substituted or unsubstituted aryl group having 6 to 30 carbon atomsfor forming a ring, a substituted or unsubstitued heteroaryl grouphaving 1 to 30 carbon atoms for forming a ring, or a substituted orunsubstituted aryl group or heteroaryl group formed via condensation ofoptional adjacent substituents; Ar₁ and Ar₂ are each independently asubstituted or unsubstituted aryl group having 6 to 50 carbon atoms forforming a ring, or a substituted or unsubstituted heteroaryl grouphaving 5 to 50 carbon atoms for forming a ring; L₁ to L₃ are eachindependently a direct linkage, a substituted or unsubstituted alkylenegroup having 1 to 15 carbon atoms, a substituted or unsubstitutedaralkylene group having 7 to 30 carbon atoms, a substituted orunsubstituted arylene group having 6 to 30 carbon atoms for forming aring, a substituted or unsubstituted heteroarylene group having 1 to 30carbon atoms for forming a ring, or a substituted or unsubstituteddivalent silyl group; m is an integer from 0 to 3; and n is an integerfrom 0 to 4.

In accordance with this aspect, the emission efficiency and emissionlife of the organic EL device may be further increased.

In an embodiment, the intermediate hole transport material may be acompound represented by Formula 2.

In Formula 2, Ar₇ to Ar₉ are each independently a substituted orunsubstituted aryl group having 6 to 50 carbon atoms for forming a ring,or a substituted or unsubstituted heteroaryl group having 5 to 50 carbonatoms for forming a ring; Ar₁₀ is hydrogen, deuterium, a halogen atom, asubstituted or unsubstituted aryl group having 6 to 50 carbon atoms forforming a ring, a substituted or unsubstituted heteroaryl group having 5to 50 carbon atoms for forming a ring, or a substituted or unsubstitutedalkyl group having 1 to 50 carbon atoms; and L₄ is a direct linkage, asubstituted or unsubstituted arylene group having 6 to 18 carbon atomsfor forming a ring, or a substituted or unsubstituted heteroarylenegroup having 5 to 15 carbon atoms for forming a ring.

In accordance with this aspect, the emission efficiency and emissionlife of the organic EL device may be further increased.

In an embodiment, the electron accepting material may have a lowestunoccupied molecular orbital (LUMO) level within a range from about −9.0eV to about −4.0 eV.

In accordance with this aspect, the emission efficiency and emissionlife of the organic EL device may be further increased.

In an embodiment, the anode-side hole transport layer may be adjacent tothe anode.

In accordance with this aspect, the emission efficiency and emissionlife of the organic EL device may be further increased.

In an embodiment, the anode-side hole transport material may be acompound represented by Formula 2.

In accordance with this aspect, the emission efficiency and emissionlife of the organic EL device may be further increased.

In an embodiment, the emission layer may include a compound representedby Formula 3.

In Formula 3, Ar₁₁ is each independently hydrogen, deuterium, asubstituted or unsubstituted alkyl group having 1 to 50 carbon atoms, asubstituted or unsubstituted cycloalkyl group having 3 to 50 carbonatoms for forming a ring, a substituted or unsubstituted alkoxy grouphaving 1 to 50 carbon atoms, a substituted or unsubstituted aralkylgroup having 7 to 50 carbon atoms, a substituted or unsubstitutedaryloxy group having 6 to 50 carbon atoms for forming a ring, asubstituted or unsubstituted arylthio group having 6 to 50 carbon atomsfor forming a ring, a substituted or unsubstituted alkoxycarbonyl grouphaving 2 to 50 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 50 carbon atoms for forming a ring, a substituted orunsubstituted heteroaryl group having 5 to 50 carbon atoms for forming aring, a substituted or unsubstituted silyl group, a carboxyl group, ahalogen atom, a cyano group, a nitro group, or a hydroxyl group; and ois an integer from 1 to 10.

In accordance with this aspect, the emission efficiency and emissionlife of the organic EL device may be further increased.

According to an embodiments of the present disclosure, an organic ELdevice includes an anode; an emission layer; an anode-side holetransport layer between the anode and the emission layer, the anode-sidehole transport layer formed mainly utilizing an electron acceptingmaterial; an intermediate hole transport material layer between theanode-side hole transport layer and the emission layer, the intermediatehole transport material layer including an intermediate hole transportmaterial; and an emission layer-side hole transport layer between theintermediate hole transport material layer and the emission layer, theemission layer-side hole transport layer adjacent to the emission layerand including an emission layer-side hole transport material representedby Formula 1.

In Formula 1, Y is O or S; R₁ to R₆ are each independently hydrogen,deuterium, a halogen atom, a substituted or unsubstituted alkyl grouphaving 1 to 15 carbon atoms, a substituted or unsubstituted silyl group,a substituted or unsubstituted aryl group having 6 to 30 carbon atomsfor forming a ring, a substituted or unsubstituted heteroaryl grouphaving 1 to 30 carbon atoms for forming a ring, or a substituted orunsubstituted aryl group or heteroaryl group formed via condensation ofoptional adjacent substituents; Ar₁ and Ar₂ are each independently asubstituted or unsubstituted aryl group having 6 to 30 carbon atoms forforming a ring, or a substituted or unsubstituted heteroaryl grouphaving 1 to 30 carbon atoms for forming a ring; L₁ to L₃ are eachindependently a direct linkage, a substituted or unsubstituted alkylenegroup having 1 to 15 carbon atoms, a substituted or unsubstitutedaralkylene group having 7 to 30 carbon atoms, a substituted orunsubstituted arylene group having 6 to 30 carbon atoms for forming aring, a substituted or unsubstituted heteroarylene group having 1 to 30carbon atoms for forming a ring, or a substituted or unsubstituteddivalent silyl group; m is an integer from 0 to 3; and n is an integerfrom 0 to 4.

In accordance with this aspect, the driving voltage of the organic ELdevice may decrease, and the emission efficiency and emission lifethereof may be increased.

In some embodiments, the intermediate hole transport material may be acompound represented by Formula 2.

In Formula 2, Ar₇ to Ar₉ are each independently a substituted orunsubstituted aryl group having 6 to 50 carbon atoms for forming a ring,or a substituted or unsubstituted heteroaryl group having 5 to 50 carbonatoms for forming a ring; Ar₁₀ is hydrogen, deuterium, a halogen atom, asubstituted or unsubstituted aryl group having 6 to 50 carbon atoms forforming a ring, a substituted or unsubstituted heteroaryl group having 5to 50 carbon atoms for forming a ring, or a substituted or unsubstitutedalkyl group having 1 to 50 carbon atoms; and L₄ is a direct linkage, asubstituted or unsubstituted arylene group having 6 to 18 carbon atomsfor forming a ring, or a substituted or unsubstituted heteroarylenegroup having 5 to 15 carbon atoms for forming a ring.

In accordance with this aspect, the driving voltage of the organic ELdevice may decrease, and the emission efficiency and emission lifethereof may be further increased.

In some embodiments, the electron accepting material may have a LUMOlevel within a range from about −9.0 eV to about −4.0 eV.

In accordance with this aspect, the driving voltage of the organic ELdevice may decrease further, and the emission efficiency and emissionlife thereof may be further increased.

In some embodiments, the anode-side hole transport layer may be adjacentto the anode.

In accordance with this aspect, the driving voltage of the organic ELdevice may decrease further, and the emission efficiency and emissionlife thereof may be further increased.

In some embodiments, the emission layer may include a compoundrepresented by Formula 3.

In Formula 3, Ar₁₁ is each independently hydrogen, deuterium, asubstituted or unsubstituted alkyl group having 1 to 50 carbon atoms, asubstituted or unsubstituted cycloalkyl group having 3 to 50 carbonatoms for forming a ring, a substituted or unsubstituted alkoxy grouphaving 1 to 50 carbon atoms, a substituted or unsubstituted aralkylgroup having 7 to 50 carbon atoms, a substituted or unsubstitutedaryloxy group having 6 to 50 carbon atoms for forming a ring, asubstituted or unsubstituted arylthio group having 6 to 50 carbon atomsfor forming a ring, a substituted or unsubstituted alkoxycarbonyl grouphaving 2 to 50 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 50 carbon atoms for forming a ring, a substituted orunsubstituted heteroaryl group having 5 to 50 carbon atoms for forming aring, a substituted or unsubstituted silyl group, a carboxyl group, ahalogen atom, a cyano group, a nitro group, or a hydroxyl group; and ois an integer from 1 to 10.

In accordance with this aspect, the driving voltage of the organic ELdevice may decrease further, and the emission efficiency and emissionlife thereof may be further increased.

BRIEF DESCRIPTION OF THE FIGURE

The accompanying drawing is included to provide a further understandingof the present disclosure, and is incorporated in and constitutes a partof this specification. The drawing illustrates example embodiments ofthe present disclosure and, together with the description, serves toexplain principles of the present disclosure. The drawing is a diagramfor explaining the schematic configuration of an organic EL deviceaccording to an embodiment.

DETAILED DESCRIPTION

Example embodiments of the present disclosure will be described below inmore detail with reference to the accompanying drawing. In thespecification and drawing, elements having substantially the samefunction will be designated by the same reference numerals, and repeatedexplanation thereof will not be provided.

<1-1. Configuration of Organic EL Device>

(1-1-1. Whole Configuration)

First, on the basis of the drawing, the whole configuration of anorganic EL device 100 according to an embodiment of the presentdisclosure will be described.

As shown in the drawing, an organic EL device 100 according to anembodiment may include a substrate 110, a first electrode 120 disposedon the substrate 110, a hole transport layer 130 disposed on the firstelectrode 120, an emission layer 140 disposed on the hole transportlayer 130, an electron transport layer 150 disposed on the emissionlayer 140, an electron injection layer 160 disposed on the electrontransport layer 150, and a second electrode 170 disposed on the electroninjection layer 160. Here, the hole transport layer 130 may be formed tohave a multi-layer structure composed of a plurality of layers 131, 133and 135.

(1-1-2. Configuration of substrate)

The substrate 110 may be a substrate utilized in a common (e.g., anexisting) organic EL device. For example, the substrate 110 may be aglass substrate, a semiconductor substrate or a transparent plasticsubstrate.

(1-1-3. Configuration of First Electrode)

The first electrode 120 may be, for example, an anode, and may be formedon the substrate 110 by an evaporation method, a sputtering method, etc.For example, the first electrode 120 may be formed as a transmissionelectrode utilizing a metal, an alloy, a conductive compound, etc.,having high work function. The first electrode 120 may be formedutilizing, for example, indium tin oxide (In₂O₃—SnO₂: ITO), indium zincoxide (In₂O₃—ZnO: IZO), tin oxide (SnO₂), zinc oxide (ZnO), etc., havinggood transparency and conductivity. In addition, the first electrode 120may be formed as a reflection electrode formed by stacking a transparentand conductive layer, such as magnesium (Mg), aluminum (Al), etc.

(1-1-4. Configuration of Hole Transport Layer)

The hole transport layer 130 may include a hole transport material andhave hole transporting function. The hole transport layer 130 may beformed, for example, on the first electrode 120 to a layer thickness(total layer thickness in a multi-layer structure) within a range fromabout 10 nm to about 150 nm.

Here, the hole transport layer 130 of the organic EL device 100according to an embodiment may be formed as a multi-layer by stackingfrom the first electrode 120, an anode-side hole transport layer 131, anintermediate hole transport material layer 133 and an emissionlayer-side hole transport layer 135 one by one. In addition, the ratioof the thicknesses of the layers is not specifically limited.

(1-1-4-1. Configuration of Anode-Side Hole Transport Layer)

The anode-side hole transport layer 131 may be a layer including ananode-side hole transport material and being doped with an electronaccepting material. For example, the anode-side hole transport layer 131may be formed on the first electrode 120.

The anode-side hole transport layer 131 may be doped with the electronaccepting material, and hole injection property from the first electrode120 may be improved. Thus, in one embodiment, the anode-side holetransport layer 131 may be provided near the first electrode 120, andfor example, may be provided adjacent to the first electrode 120.

The anode-side hole transport material included in the anode-side holetransport layer 131 may be any suitable hole transport material.Examples of the anode-side hole transport material included in theanode-side hole transport layer 131 may be1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), a carbazolederivative (such as N-phenyl carbazole or polyvinyl carbazole),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine(TPD), 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB), etc.

The electron accepting material included in the anode-side holetransport layer 131 may be any suitable electron accepting material.However, in one embodiment, the electron accepting material doped in theanode-side hole transport layer 131 may have a LUMO level from about−9.0 eV to about —4.0 eV, and for example, the electron acceptingmaterial doped in the anode-side hole transport layer 131 may have theLUMO level from about −6.0 eV to about −4.0 eV.

Here, examples of the electron accepting material having the LUMO levelfrom about −9.0 eV to about −4.0 eV may include the compoundsrepresented by Formulae 4-1 to 4-14.

In the above Formulae 4-1 to 4-14, R is hydrogen, deuterium, a halogenatom, a fluoroalkyl group having 1 to 50 carbon atoms, a cyano group, analkoxy group having 1 to 50 carbon atoms, an alkyl group having 1 to 50carbon atoms, an aryl group having 6 to 50 carbon atoms or a heteroarylgroup having 5 to 50 carbon atoms for forming a ring.

Ar is a substituted with an electron withdrawing group (e.g., asubstituted aryl group having 6 to 50 carbon atoms for forming a ringand substituted with an electron withdrawing group) or an unsubstitutedaryl group having 6 to 50 carbon atoms for forming a ring, or asubstituted or unsubstituted heteroaryl group having 5 to 50 carbonatoms for forming a ring; Y is a methine group (—CH═) or a nitrogen atom(—N═); Z is a pseudohalogen atom or a sulfur (S) atom; n is an integerof 10 and less; and X is one of the substituents represented by thefollowing formulae X1 to X7.

In the above Formulae X₁ to X₇, Ra is hydrogen, deuterium, a halogenatom, a fluoroalkyl group having 1 to 50 carbon atoms, a cyano group, analkoxy group having 1 to 50 carbon atoms, an alkyl group having 1 to 50carbon atoms, a substituted or unsubstituted aryl group having 6 to 50carbon atoms for forming a ring, or a substituted or unsubstitutedheteroaryl group having 5 to 50 carbon atoms for forming a ring.

Examples of the substituted or unsubstituted aryl group having 6 to 50carbon atoms for forming a ring represented by R, Ar and Ra may includea phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthrylgroup, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a9-phenanthryl group, a 1-naphthacenyl group, a 2-naphthacenyl group, a9-naphthacenyl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenylgroup, a 2-biphenylyl group, a 3-biphenylyl group, a 4-biphenylyl group,a p-terphenyl-4-yl group, a p-terphenyl-3-yl group, a p-terphenyl-2-ylgroup, an m-terphenyl-4-yl group, an m-terphenyl-3-yl group, anm-terphenyl-2-yl group, an o-tolyl group, an m-tolyl group, a p-tolylgroup, a p-t-butyl phenyl group, a p-(1-2-phenylpropyl)phenyl group, a3-methyl-2-naphthyl group, a 4-methyl-1-naphthyl group, a4-methyl-1-anthryl group, a 4′-methyl biphenylyl group, a4″-t-butyl-p-terphenyl-4-yl group, a fluoranthenyl group, a fluorenylgroup, etc.

Examples of the substituted or unsubstituted heteroaryl group having 5to 50 carbon atoms for forming a ring represented by R, Ar and Ra mayinclude a 1-pyrrolyl group, a 2-pyrrolyl group, a 3-pyrrolyl group, apyridinyl group, a 2-pyridinyl group, a 3-pyridinyl group, a 4-pyridinylgroup, a 1-indolyl group, a 2-indolyl group, a 3-indolyl group, a4-indolyl group, a 5-indolyl group, a 6-indolyl group, a 7-indolylgroup, a 1-isoindolyl group, a 2-isoindolyl group, a 3-isoindolyl group,a 4-isoindolyl group, a 5-isoindolyl group, a 6-isoindolyl group, a7-isoindolyl group, a 2-furyl group, a 3-furyl group, a 2-benzofuranylgroup, a 3-benzofuranyl group, a 4-benzofuranyl group, a 5-benzofuranylgroup, a 6-benzofuranyl group, a 7-benzofuranyl group, a1-isobenzofuranyl group, a 3-isobenzofuranyl group, a 4-isobenzofuranylgroup, a 5-isobenzofuranyl group, a 6-isobenzofuranyl group, a7-isobenzofuranyl group, a quinolyl group, a 3-quinolyl group, a4-quinolyl group, a 5-quinolyl group, a 6-quinolyl group, a 7-quinolylgroup, an 8-quinolyl group, a 1-isoquinolyl group, a 3-isoquinolylgroup, a 4-isoquinolyl group, a 5-isoquinolyl group, a 6-isoquinolylgroup, a 7-isoquinolyl group, an 8-isoquinolyl group, a 2-quinoxalinylgroup, a 5-quinoxalinyl group, a 6-quinoxalinyl group, a 1-carbazolylgroup, a 2-carbazolyl group, a 3-carbazolyl group, a 4-carbazolyl group,a 9-carbazolyl group, a 1-phenanthridinyl group, a 2-phenanthridinylgroup, a 3-phenanthridinyl group, a 4-phenanthridinyl group, a6-phenanthridinyl group, a 7-phenanthridinyl group, an 8-phenanthridinylgroup, a 9-phenanthridinyl group, a 10-phenanthridinyl group, a1-acridinyl group, a 2-acridinyl group, a 3-acridinyl group, a4-acridinyl group, a 9-acridinyl group, a 1,7-phenanthroline-2-yl group,a 1,7-phenanthroline-3-yl group, a 1,7-phenanthroline-4-yl group, a1,7-phenanthroline-5-yl group, a 1,7-phenanthroline-6-yl group, a1,7-phenanthroline-8-yl group, a 1,7-phenanthroline-9-yl group, a1,7-phenanthroline-10-yl group, a 1,8-phenanthroline-2-yl group, a1,8-phenanthroline-3-yl group, a 1,8-phenanthroline-4-yl group, a1,8-phenanthroline-5-yl group, a 1,8-phenanthroline-6-yl group, a1,8-phenanthroline-7-yl group, a 1,8-phenanthroline-9-yl group, a1,8-phenanthroline-10-yl group, a 1,9-phenanthroline-2-yl group, a1,9-phenanthroline-3-yl group, a 1,9-phenanthroline-4-yl group, a1,9-phenanthroline-5-yl group, a 1,9-phenanthroline-6-yl group, a1,9-phenanthroline-7-yl group, a 1,9-phenanthroline-8-yl group, a1,9-phenanthroline-10-ylgroup, a 1,10-phenanthroline-2-yl group, a1,10-phenanthroline-3-yl group, a 1,10-phenanthroline-4-yl group, a1,10-phenanthroline-5-yl group, a 2,9-phenanthroline-1-yl group, a2,9-phenanthroline-3-yl group, a 2,9-phenanthroline-4-yl group, a2,9-phenanthroline-5-yl group, a 2,9-phenanthroline-6-yl group, a2,9-phenanthroline-7-yl group, a 2,9-phenanthroline-8-yl group, a2,9phenanthroline-10-yl group, a 2,8-phenanthroline-1-yl group, a2,8-phenanthroline-3-yl group, a 2,8-phenanthroline-4-yl group, a2,8-phenanthroline-5-yl group, a 2,8-phenanthroline-6-yl group, a 2,8-phenanthroline-7-yl group, a 2,8-phenanthroline-9-yl group, a2,8-phenanthroline-10-yl group, a 2,7-phenanthroline-1-yl group, a2,7-phenanthroline-3-yl group, a 2,7-phenanthroline-4-yl group, a2,7-phenanthroline-5-yl group, a 2,7-phenanthroline-6-yl group, a2,7-phenanthroline-8-yl group, a 2,7-phenanthroline-9-yl group, a2,7-phenanthroline-l0-yl group, a 1-phenazinyl group, a 2-phenazinylgroup, a 1-phenothiazinyl group, a 2-phenothiazinyl group, a3-phenothiazinyl group, a 4-phenothiazinyl group, a 10-phenothiazinylgroup, a 1-phenoxaziny group, a 2-phenoxazinyl group, a 3-phenoxazinylgroup, a 4-phenoxazinyl group, a 10-phenoxazinyl group, a 2-oxazolylgroup, a 4-oxazolyl group, a 5-oxazolyl group, a 2-oxadiazolyl group, a5-oxadiazolyl group, a 3-furazanyl group, a 2-thienyl group, a 3-thienylgroup, a 2-methylpyrrole-1-yl group, a 2-methylpyrrole-3-yl group, a2-methylpyrrole-4-yl group, a 2-methylpyrrole-5-yl group, a3-methylpyrrole-1-yl group, a 3-methylpyrrole-2-yl group, a3-methylpyrrole-4-yl group, a 3-methylpyrrole-5-yl group, a2-t-butylpyrrole-4-yl group, a 3-(1-2-phenylpropyl) pyrrole-1-yl group,a 2-methyl-1-indolyl group, a 4-methyl-1-indolyl group, a2-methyl-3-indolyl group, a 4-methyl-3-indolyl group, a2-t-butyl-1-indolyl group, a 4-t-butyl-1-indolyl group, a2-t-butyl-3-indolyl group, a 4-t-butyl-3-indolyl group, etc.

Examples of the fluoroalkyl group in the substituted or unsubstitutedfluoroalkyl group having 1 to 50 carbon atoms represented by R and Ramay include a perfluoroalkyl group (such as a trifluoromethyl group, apentafluoroethyl group, a heptafluoropropyl group or aheptadecafluorooctane group), a monofluoromethyl group, a difluoromethylgroup, a trifluoroethyl group, a tetrafluoropropyl group, anoctafluoropentyl group, etc.

Examples of the substituted or unsubstituted alkyl group having 1 to 50carbon atoms represented by R and Ra may include a methyl group, anethyl group, a propyl group, an isopropyl group, an n-butyl group, ans-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, ann-hexyl group, an n-heptyl group, an n-octyl group, a hydroxymethylgroup, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a2-hydroxyisobutyl group, a 1,2-dihydroxyethyl group, a1,3-dihydroxyisopropyl group, a 2,3-dihydroxy-t-butyl group, a1,2,3-trihydroxypropyl group, a chloromethyl group, a 1-chloroethylgroup, a 2-chloroethyl group, a 2-chloroisobutyl group, a1,2-dichloroethyl group, a 1,3-dichloroisopropyl group, a2,3-dichloro-t-butyl group, a 1,2,3-trichloropropyl group, a bromomethylgroup, a 1-bromoethyl group, a 2-bromoethyl group, a 2-bromoisobutylgroup, a 1,2-dibromoethyl group, a 1,3-dibromoisopropyl group, a2,3-dibromo-t-butyl group, a 1,2,3-tribromopropyl group, an iodomethylgroup, a 1-iodoethyl group, a 2-iodoethyl group, a 2-iodoisobutyl group,a 1,2-diiodoethyl group, a 1,3-diiodoisopropyl group, a2,3-diiodo-t-butyl group, a 1,2,3-triiodopropyl group, an aminomethylgroup, a 1-aminoethyl group, a 2-aminoethyl group, a 2-aminoisobutylgroup, a 1,2-diaminoethyl group, a 1,3-diaminoisopropyl group, a2,3-diamino-t-butyl group, a 1,2,3-triaminopropyl group, a cyanomethylgroup, a 1-cyanoethyl group, a 2-cyanoethyl group, a 2-cyanoisobutylgroup, a 1,2-dicyanoethyl group, a 1,3-dicyanoisopropyl group, a2,3-dicyano-t-butyl group, a 1,2,3-tricyanopropyl group, a nitromethylgroup, a 1-nitroethyl group, a 2-nitroethyl group, a 2-nitroisobutylgroup, a 1,2-dinitroethyl group, a 1,3-dinitroisopropyl group, a2,3-dinitro-t-butyl group, a 1,2,3-trinitropropyl group, a cyclopropylgroup, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a4-methylcyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a1-norbornyl group, a 2-norbornyl group, etc.

The substituted or unsubstituted alkoxy group having 1 to 50 carbonatoms represented by R and Ra may be a group represented by —OY.Examples of Y may include a methyl group, an ethyl group, a propylgroup, an isopropyl group, an n-butyl group, an s-butyl group, anisobutyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, ann-heptyl group, an n-octyl group, a hydroxymethyl group, a1-hydroxyethyl group, a 2-hydroxyethyl group, a 2-hydroxyisobutyl group,a 1,2-dihydroxyethyl group, a 1,3-dihydroxyisopropyl group, a2,3-dihydroxy-t-butyl group, a 1,2,3-trihydroxypropyl group, achloromethyl group, a 1-chloroethyl group, a 2-chloroethyl group, a2-chloroisobutyl group, a 1,2-dichloroethyl group, a1,3-dichloroisopropyl group, a 2,3-dichloro-t-butyl group, a1,2,3-trichloropropyl group, a bromomethyl group, a 1-bromoethyl group,a 2-bromoethyl group, a 2-bromoisobutyl group, a 1,2-dibromoethyl group,a 1,3-dibromoisopropyl group, a 2,3-dibromo-t-butyl group, a1,2,3-tribromopropyl group, an iodomethyl group, a 1-iodoethyl group, a2-iodoethyl group, a 2-iodoisobutyl group, a 1,2-diiodoethyl group, a1,3-diiodoisopropyl group, a 2,3-diiodo-t-butyl group, a1,2,3-triiodopropyl group, an aminomethyl group, a 1-aminoethyl group, a2-aminoethyl group, a 2-aminoisobutyl group, a 1,2-diaminoethyl group, a1,3-diaminoisopropyl group, a 2,3-diamino-t-butyl group, a1,2,3-triaminopropyl group, a cyanomethyl group, a 1-cyanoethyl group, a2-cyanoethyl group, a 2-cyanoisobutyl group, a 1,2-dicyanoethyl group, a1,3-dicyanoisopropyl group, a 2,3-dicyano-t-butyl group, a1,2,3-tricyanopropyl group, a nitromethyl group, a 1-nitroethyl group, a2-nitroethyl group, a 2-nitroisobutyl group, a 1,2-dinitroethyl group, a1,3-dinitroisopropyl group, a 2,3-dinitro-t-butyl group, a1,2,3-trinitropropyl group, etc.

Examples of the halogen atom represented by R and Ra may includefluorine (F), chlorine (Cl), bromine (Br), iodine (I), etc.

Here, example compounds of the electron accepting material may includethe following Compounds 4-15 and 4-16. For example, the LUMO level ofCompound 4-15 may be about −4.40 eV, and the LUMO level of Compound 4-16may be about −5.20 eV. However, the electron accepting material is notlimited to the following Compounds 4-15 and 4-16.

In addition, the amount doped of the electron accepting material may bean amount capable of being doped into the anode-side hole transportlayer 131, without any limitation (e.g., the amount of the electronaccepting material doped into or included in the anode-side holetransport layer 131 is not particularly limited and may be any suitableamount). For example, the amount doped of the electron acceptingmaterial may be from about 0.1 wt % to about 50 wt % on the basis of thetotal amount of the anode-side hole transport material included in theanode-side hole transport layer 131, and may be from about 0.5 wt % toabout 5 wt %.

(1-1-4-2. Configuration of Intermediate Hole Transport Material Layer)

The intermediate hole transport material layer 133 may include anintermediate hole transport material. The intermediate hole transportmaterial layer 133 may be formed, for example, on the anode-side holetransport layer 131.

The intermediate hole transport material included in the intermediatehole transport material layer 133 may be any suitable hole transportmaterial. For example, the intermediate hole transport material mayutilize the above-mentioned hole transport materials as the anode-sidehole transport materials.

However, in one embodiment, the intermediate hole transport material maybe a compound represented by the following Formula 2.

In the above Formula 2, Ar₇ to Ar₉ are each independently a substitutedor unsubstituted aryl group having 6 to 50 carbon atoms for forming aring or a substituted or unsubstituted heteroaryl group having 5 to 50carbon atoms for forming a ring; Ar₁₀ is hydrogen, deuterium, a halogenatom, a substituted or unsubstituted aryl group having 6 to 50 carbonatoms for forming a ring, a substituted or unsubstituted heteroarylgroup having 5 to 50 carbon atoms for forming a ring or a substituted orunsubstituted alkyl group having 1 to 50 carbon atoms; and L₄ is adirect linkage, a substituted or unsubstituted arylene group having 6 to18 carbon atoms for forming a ring or a substituted or unsubstitutedheteroarylene group having 5 to 15 carbon atoms for forming a ring.

Examples of Ar₇ to Ar₉ may include a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, an anthryl group, a phenanthrylgroup, a fluorenyl group, an indenyl group, a pyrenyl group, anacetonaphthenyl group, a fluoranthenyl group, a triphenylenyl group, apyridyl group, a furanyl group, a pyranyl group, a thienyl group, aquinolyl group, an isoquinolyl group, a benzofuranyl group, abenzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolylgroup, a benzothiazolyl group, a quinoxalyl group, a pyrazolyl group, adibenzofuranyl group, a dibenzothienyl group, etc. In one embodiment,examples of Ar₇ to Ar₉ may include the phenyl group, the biphenyl group,the terphenyl group, the fluorenyl group, the carbazolyl group, thedibenzofuranyl group, etc.

Examples of Ar₁₀ may include a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, an anthryl group, a phenanthrylgroup, a fluorenyl group, an indenyl group, a pyrenyl group, anacetonaphthenyl group, a fluoranthenyl group, a triphenylenyl group, apyridyl group, a furanyl group, a pyranyl group, a thienyl group, aquinolyl group, an isoquinolyl group, a benzofuranyl group, abenzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolylgroup, a benzothiazolyl group, a quinoxalyl group, a pyrazolyl group, adibenzofuranyl group, a dibenzothienyl group, a methyl group, an ethylgroup, a propyl group, an isopropyl group, an n-butyl group, etc. In oneembodiment, examples of Ar₁₁ may include the phenyl group, the biphenylgroup, the terphenyl group, the fluorenyl group, the carbazolyl group,the dibenzofuranyl group, etc.

Examples of L₄ other than the direct linkage may include a phenylenegroup, a biphenylene group, a terphenylene group, a naphthylene group,an anthrylene group, a phenanthrylene group, a fluorenylene group, anindenylene group, a pyrenylene group, an acetonaphthenylene group, afluoranthenylene group, a triphenylenylene group, a pyridylene group, afuranylene group, a pyranylene group, a thienylene group, a quinolylenegroup, an isoquinolylene group, a benzofuranylene group, abenzothienylene group, an indolylene group, a carbazolylene group, abenzoxazolylene group, a benzothiazolylene group, a kinokisariren group,a benzoimidazolylene group, a pyrazolylene group, a dibenzofuranylenegroup, a dibenzothienylene group, etc. In one embodiment, L₄ may includethe direct linkage, the phenylene group, the biphenylene group, theterphenylene group, the fluorenylene group, the carbazolylene group orthe dibenzofuranylene group.

Examples of the compound represented by Formula 2 may include thefollowing Compounds 2-1 to 2-17. However, the compound represented byFormula 2 is not limited to the following Compounds 2-1 to 2-17.

The intermediate hole transport material layer 133 may include thecompound represented by the above Formula 2 as the intermediate holetransport material and may improve the hole transporting property of thehole transport layer 130. Thus, the emission efficiency and emissionlife of the organic EL device 100 may be improved.

In addition, the compound represented by Formula 2 may be included inthe anode-side hole transport layer 131 as the anode-side hole transportmaterial. In the case that the anode-side hole transport layer 131includes the compound represented by Formula 2 as the anode-side holetransport material, the hole transporting property of the hole transportlayer 130 may be improved. Thus, the emission efficiency and emissionlife of the organic EL device 100 may be improved.

(1-1-4-3. Configuration of Emission Layer-Side Hole Transport Layer)

The emission layer-side hole transport layer 135 may include a compoundrepresented by the following Formula 1. The emission layer-side holetransport layer 135 may be formed, for example, on the intermediate holetransport material layer 133, adjacent to the emission layer 140.

In Formula 1, Y is O or S; R₁ to R₆ are each independently hydrogen,deuterium, a halogen atom, a substituted or unsubstituted alkyl grouphaving 1 to 15 carbon atoms, a substituted or unsubstituted silyl group,a substituted or unsubstituted aryl group having 6 to 30 carbon atomsfor forming a ring, a substituted or unsubstituted heteroaryl grouphaving 1 to 30 carbon atoms for forming a ring, or a substituted orunsubstituted aryl group or heteroaryl group formed via condensation ofoptional adjacent substituents; Ar₁ and Ar₂ are each independently asubstituted or unsubstituted aryl group having 6 to 30 carbon atoms forforming a ring, or a substituted or unsubstituted heteroaryl grouphaving 1 to 30 carbon atoms for forming a ring; L₁ to L₃ are eachindependently a direct linkage, a substituted or unsubstituted alkylenegroup having 1 to 15 carbon atoms, a substituted or unsubstitutedaralkylene group having 7 to 30 carbon atoms, a substituted orunsubstituted arylene group having 6 to 30 carbon atoms for forming aring, a substituted or unsubstituted heteroarylene group having 1 to 30carbon atoms for forming a ring, or a substituted or unsubstituteddivalent silyl group; m is an integer from 0 to 3; and n is an integerfrom 0 to 4.

Examples of R₁ to R₆ may include hydrogen, deuterium, a halogen atom, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, ananthryl group, a phenanthryl group, a fluorenyl group, an indenyl group,a pyrenyl group, an acetonaphthenyl group, a fluoranthenyl group, atriphenylenyl group, a pyridyl group, a furanyl group, a pyranyl group,a thienyl group, a quinolyl group, an isoquinolyl group, a benzofuranylgroup, a benzothienyl group, an indolyl group, a carbazolyl group, abenzoxazolyl group, a benzothiazolyl group, a quinoxalyl group, apyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, amethyl group, an ethyl group, a propyl group, an isopropyl group, ann-butyl group, etc. In one embodiment, examples of R₁ and R₆ may includethe hydrogen atom, the halogen atom, the methyl group, the phenyl group,the biphenyl group, the fluorenyl group, the carbazolyl group, and thedibenzofuranyl group.

Examples of Ar₁ and Ar₂ may include a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, an anthryl group, a phenanthrylgroup, a fluorenyl group, an indenyl group, a pyrenyl group, anacetonaphthenyl group, a fluoranthenyl group, a triphenylenyl group, apyridyl group, a furanyl group, a pyranyl group, a thienyl group, aquinolyl group, an isoquinolyl group, a benzofuranyl group, abenzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolylgroup, a benzothiazolyl group, a quinoxalyl group, a pyrazolyl group, adibenzofuranyl group, a dibenzothienyl group, etc. In one embodiment,examples of Ar₁ and Ar₂ may include the phenyl group, the biphenylgroup, the terphenyl group, the fluorenyl group, the carbazolyl group,the dibenzofuranyl group, etc.

Examples of L₁ to L₃ other than the direct linkage may be acorresponding divalent substituent of the substituents illustrated inthe above Ar₁ and Ar₂ (e.g., examples of L₁ to L₃ other than the directlinkage may be a corresponding divalent group of the groups listed abovefor Ar₁ and Ar₂). Examples of L₁ to L₃ other than the direct linkage mayinclude a phenylene group, a naphthylene group, a biphenylene group, athienothiophenylene group and a pyridylene group. In one embodiment, L₁to L₃ may be the direct linkage, the phenylene group or the biphenylenegroup.

Examples of the compound represented by Formula 1 may include thefollowing Compounds 1 to 48. However, the compound represented byFormula 1 is not limited to the following Compounds 1 to 48.

The emission layer-side hole transport layer 135 may include thecompound represented by the above Formula 1 as the emission layer-sidehole transport material and may passivate the hole transport layer 130from electrons not consumed in the emission layer 140. In addition,since the emission layer-side hole transport layer 135 includes thecompound represented by the above Formula 1, the diffusion of energy inan excited state generated in the emission layer 140 into the holetransport layer 130 may be reduced or prevented. Thus, according to thisconfiguration, the emission layer-side hole transport layer 135 mayimprove the current flow durability of the hole transport layer 130.

In addition, in one embodiment, the emission layer-side hole transportlayer 135 may be formed near the emission layer 140, for example, theemission layer-side hole transport layer 135 may be formed adjacent tothe emission layer 140 to effectively reduce or prevent the diffusion ofthe electrons or the energy from the emission layer 140.

Since the emission layer-side hole transport layer 135 includes thecompound represented by the above Formula 1, the charge balance of thewhole organic EL device 100 may be controlled, and the diffusion of theelectron accepting material doped into the anode-side hole transportlayer 131 into the emission layer 140 may be restrained (e.g., reducedor prevented). Accordingly, the emission layer-side hole transport layer135 may improve the whole charge transport property of the holetransport layer 130.

Since the emission layer-side hole transport layer 135 includes thecompound represented by the above Formula 1, the charge transportproperty and current flow durability of the hole transport layer 130 maybe improved. Thus, the emission layer-side hole transport layer 135 mayimprove the emission efficiency and emission life of the organic ELdevice 100.

As described above, the hole transport layer 130 including theanode-side hole transport layer 131, the intermediate hole transportmaterial layer 133 and the emission layer-side hole transport layer 135may improve the current flow durability and hole transport property ofthe organic EL device 100. Thus, the organic EL device 100 according toan embodiment may have improved emission efficiency and emission life.

(1-1-5. Configuration of Emission Layer)

The emission layer 140 may include a host material, a dopant material asa luminescent material, etc., and emits light via fluorescence orphosphorescence. The emission layer 140 may be formed, for example, onthe hole transport layer 130 to a layer thickness within a range fromabout 10 nm to about 60 nm.

The host material and the dopant material included in the emission layer140 may include any suitable host materials and dopant materials. Forexample, the emission layer 140 may include a fluoranthene derivative, apyrene derivative, an arylacetylene derivative, a fluorene derivative, aperylene derivative, a chrysene derivative, etc., as the host materialor the dopant material. In one embodiment, the emission layer 140 mayinclude tris(8-quinolinolato)aluminum (Alq3),4,4′-N,N′-dicarbazole-biphenyl (CBP), poly(n-vinylcarbazole) (PVK),4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI),3-tert-butyl-9,10-di(naphtho-2-yl)anthracene (TBADN), distyrylarylene(DSA), 4,4′-bis(9-carbazole)-2,2′-dimethyl-biphenyl (dmCBP),bis(2,2-diphenyl vinyl)-1,1′-biphenyl (DPVBi),1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB),4-(di-p-tolylamino)-4′-[(di-p-tolylamino)styryl]stilbene (DPAVB),N-(4-(E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine(N-BDAVBi), 2,5,8,11-tetra-t-butylperylene (TBPe), 1,1-dipyrene,1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene, etc., as thehost material or the dopant material.

In addition, the emission layer 140 may, in one embodiment, include acompound represented by the following Formula 3.

In the above Formula 3, Ar₁₁ is each independently (e.g., when o is twoor greater, each of Ar₁₁ is independently) hydrogen, deuterium, asubstituted or unsubstituted alkyl group having 1 to 50 carbon atoms, asubstituted or unsubstituted cycloalkyl group having 3 to 50 carbonatoms for forming a ring, a substituted or unsubstituted alkoxy grouphaving 1 to 50 carbon atoms, a substituted or unsubstituted aralkylgroup having 7 to 50 carbon atoms, a substituted or unsubstitutedaryloxy group having 6 to 50 carbon atoms for forming a ring, asubstituted or unsubstituted arylthio group having 6 to 50 carbon atomsfor forming a ring, a substituted or unsubstituted alkoxycarbonyl grouphaving 2 to 50 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 50 carbon atoms for forming a ring, a substituted orunsubstituted heteroaryl group having 5 to 50 carbon atoms for forming aring, a substituted or unsubstituted silyl group, a carboxyl group, ahalogen atom, a cyano group, a nitro group or a hydroxyl group; and o isan integer from 1 to 10.

In addition, examples of the compound represented by Formula 3 mayinclude the following Compounds 3-1 to 3-12. However, the compoundrepresented by Formula 3 is not limited to the following Compounds 3-1to 3-12.

In the case that the emission layer 140 includes the compoundrepresented by Formula 3, the anode-side hole transport layer 131 mayimprove the hole injection property from the first electrode 120significantly. Thus, the emission layer 140 may further improve theemission property of the organic EL device 100 by including the compoundrepresented by Formula 3.

The emission layer 140 may include the compound represented by Formula 3as the host material or as the dopant material.

The emission layer 140 may be formed as an emission layer emitting lightwith a specific color. For example, the emission layer 140 may be formedas a red emitting layer, a green emitting layer or a blue emittinglayer.

In the case that the emission layer 140 is the blue emitting layer,suitable blue dopants may be utilized. For example, perylene and thederivative thereof, and/or an iridium (Ir) complex (such asbis[2-(4,6-difluorophenyl)pyridinate]picolinate iridium(III) (Flrpic))may be utilized as the blue dopant.

In the case that the emission layer 140 is the red emitting layer,suitable red dopants may be utilized. For example, rubrene and thederivative thereof,4-dicyanomethylene-2-(p-dimethylaminostyryl)-6-methyl-4H-pyrane (DCM)and the derivative thereof, an iridium complex (such asbis(1-1-phenylisoquinoline)(acetylacetonate) iridium(III)(Ir(piq)₂(acac)), an osmium (Os) complex, a platinum complex, etc., maybe utilized as the red dopant.

In the case that the emission layer 140 is the green emitting layer,suitable green dopants may be utilized. For example, coumarin and thederivative thereof, an iridium complex (such as tris(2-phenylpyridine)iridium(III) (Ir(ppy)₃)), etc., may be utilized.

(1-1-6. Configuration of Electron Transport Layer)

The electron transport layer 150 is a layer including an electrontransport material and having electron transporting function. Theelectron transport layer 150 may be formed, for example, on the emissionlayer 140 to a layer thickness within a range from about 15 nm to about50 nm. The electron transport material included in the electrontransport layer 150 may be any suitable electron transport materials.

Examples of the suitable electron transport material may include,tris(8-hydroxyquinolinato)aluminum (Alq3) or an electron transportmaterial having a nitrogen-containing aromatic ring. Examples of theelectron transport material having a nitrogen-containing aromatic ringmay include an electron transport material including a pyridine ring(such as 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene), an electron transportmaterial including a triazine ring (such as2,4,6-tris(3′-(pyridin-3-yl)biphenyl-2-yl)-1,3,5-triazine), an electrontransport material including an imidazole derivative (such as2-(4-(N-phenylbenzoimidazolyl-1-ylphenyl)-9,10-dinaphthylanthracene)),etc.

(1-1-7. Configuration of Electron Injection Layer)

The electron injection layer 160 is a layer having function of easyinjection of electrons from the second electrode 170. The electroninjection layer 160 may be formed, for example, on the electrontransport layer 150 to a layer thickness within a range from about 0.3nm to about 9 nm. The electron injection layer 160 may be formedutilizing any suitable materials that may be utilized as materials forforming the electron injection layer 160. Examples of the material forforming the electron injection layer 160 may include a Li complex (suchas lithium 8-quinolinato (Liq) or lithium fluoride (LiF)), sodiumchloride (NaCl), cesium fluoride (CsF), lithium oxide (Li₂O), bariumoxide (BaO), etc.

(1-1-8. Configuration of Second Electrode)

The second electrode 170 may be, for example, a cathode and formed onthe electron injection layer 160 utilizing an evaporation method or asputtering method. For example, the second electrode 170 may be formedas a reflection electrode utilizing a metal, an alloy, a conductivecompound, etc., having low work function. The second electrode 170 maybe formed utilizing, a metal (such as lithium (Li), magnesium (Mg),aluminum (Al) or calcium (Ca)), or a metal mixture (such asaluminum-lithium (Al—Li), magnesium-indium (Mg—In) or magnesium-silver(Mg—Ag)). In addition, the second electrode 170 may be formed as a thinfilm of a metal material, having a thickness of about 20 nm, or less(e.g., not greater than 20 nm) and may be formed as a transmissionelectrode utilizing ITO, IZO, etc.

(1-1-9. Modification Example of Organic EL Device)

In addition, the structure of the organic EL device 100 shown in thedrawing is only an illustration, and the organic EL device 100 accordingto an embodiment is not limited to the structure of the drawing. In theorganic EL device 100 according to an embodiment, some layers may beformed as a multi-layer, or another layer may be additionally formed. Inthe organic EL device 100 according to an embodiment, at least one ofthe electron transport layer 150 and the electron injection layer 160may not be provided.

In the organic EL device 100 according to an embodiment, a holeinjection layer may be provided between the first electrode 120 and thehole transport layer 130.

The hole injection layer is a layer having the function of easyinjection of holes from the first electrode 120. The hole injectionlayer may be formed, for example, on the first electrode 120 to a layerthickness within a range from about 10 nm to about 150 nm. The holeinjection layer may be formed utilizing any suitable materials forforming the hole injection layer. Examples of the material for formingthe hole injection layer may include a triphenylamine-containingpolyether ketone (TPAPEK), 4-isopropyl-4′-methyldiphenyliodoniumtetrakis(pentafluorophenyl)borate (PPBI),N,N′-diphenyl-N,N′-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4′-diamine(DNTPD), a phthalocyanine compound (such as copper phthalocyanine),4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA),N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB),4,4′,4″-tris{N,N-diamino}triphenylamine (TDATA),4,4′,4″-tris(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA),polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphorsulfonic acid (Pani/CSA) orpolyaniline/poly(4-styrenesulfonate) (PANI/PSS), etc.

(1-1-10. Method of Manufacturing Organic EL Device)

Each layer of the organic EL device 100 according to an embodiment asdescribed above may be formed by selecting an appropriate layer formingmethod depending on materials utilized, such as vacuum evaporation,sputtering, or various other suitable coating methods.

For example, a metal layer such as the first electrode 120, the secondelectrode 170, or the electron injection layer 160 may be formedutilizing an evaporation method (including an electron beam evaporationmethod, a hot filament evaporation method and/or a vacuum evaporationmethod), a sputtering method, and/or a plating method (including anelectroplating method and/or an electroless plating method).

An organic layer (such as the hole transport layer 130, the emissionlayer 140 or the electron transport layer 150) may be formed utilizing aphysical vapor deposition (PVD) method (such as a vacuum depositionmethod), a printing method (such as a screen printing method or an inkjet printing method), a laser transcription method and/or a coatingmethod (such as a spin coating method).

Hereinabove, an embodiment of the organic EL device 100 according to anembodiment has been explained in more detail.

EXAMPLES 1-2. Examples

Hereinafter, organic EL devices according to example embodiments will beexplained in more detail referring to examples and comparative examples.The following embodiments are only for illustration, and the organic ELdevices according to example embodiments are not limited thereto.

(1-2-1. Synthesis of Compound Represented by Formula 1)

First, a synthetic method of a compound represented by Formula 1 will beexplained in more detail referring to synthetic methods of Compounds 1and 5. The following embodiments are only for illustration, and thesynthetic methods of the compound represented by Formula 1 are notlimited thereto.

(1-2-1-1. Synthesis of Compound 1)

According to the following Reaction 1, Compound 1, which is the compoundrepresented by Formula 1, was synthesized. The product thus obtained wasidentified by measuring physical properties by means of ¹HNMR andFAB-MS.

(Synthesis of Compound A)

Under an Ar atmosphere, 53.8 g ofN-[1,1′-biphenyl]-4-yl-N-(4-bromophenyl)-[1,1′-biphenyl]-4-amine, 6.46 gof Pd(dppf)Cl₂.CH₂Cl₂, 33.3 g of KOAc and 33.0 g ofbis(pinacolato)diboron were added to a 2 L flask, followed by degassingunder vacuum and stirring in a dioxane solvent at about 100° C. forabout 12 hours. Then, solvents were distilled from the reactant, CH₂Cl₂and water were added thereto, and an organic phase was separated. To theseparated organic phase, magnesium sulfate (Mg₂SO₄) and activated claywere added, filtering with suction was performed, and the solvent wasdistilled. The crude product thus obtained was separated by silica gelcolumn chromatography utilizing a mixture solvent of dichloromethane andhexane, to produce 56.8 g (Yield 98%) of Compound A as a white solid(FAB-MS: C₃₆H₃₄BNO₂, measured value 523).

(Synthesis of Compound B)

Under an Ar atmosphere, 10.0 g of Compound A, 6.00 g of1-iodo-3-bromobenzene, 1.54 g of Pd(PPh₃)₄, and 5.25 g of potassiumcarbonate (K₂CO₃) were added to a 300 mL, three necked flask, followedby heating and stirring in a mixture solvent of 450 mL of toluene and 60mL of water at about 90° C. for about 8 hours. After air cooling, waterwas added to the reactant, an organic phase was separated, and solventswere distilled from the separated organic phase. The crude product thusobtained was separated by silica gel column chromatography utilizing amixture solvent of dichloromethane and hexane and recrystallizedutilizing a mixture solvent of toluene and hexane to produce 9.29 g(Yield 88%) of Compound B as a white solid (FAB-MS: C₃₆H₂₆BrN, measuredvalue 551).

(Synthesis of Compound 1)

Under an Ar atmosphere, 3.10 g of Compound B, 1.2 g ofdibenzofuran-4-boronic acid, 0.84 g of Pd(PPh₃)₄, and 2.35 g ofpotassium carbonate (K₂CO₃) were added to a 500 mL, three necked flask,followed by heating and stirring in a mixture solvent of 170 mL oftoluene and 80 mL of water at about 90° C. for about 8 hours. After aircooling, water was added to the reactant, an organic phase wasseparated, and solvents were distilled from the separated organic phase.The crude product thus obtained was separated by silica gel columnchromatography utilizing a mixture solvent of dichloromethane and hexaneand recrystallized utilizing a mixture solvent of toluene and hexane toproduce 3.08 g (Yield 86%) of Compound 1 as a white solid. Chemicalshift values (δ) of Compound 1 by ¹HNMR (300 MHz, CDCl₃) were 8.11 (s,1H), 8.00 (d, J=7.6 Hz, 1H), 7.96 (d, J=7.6 Hz, 1H), 7.87 (d, J=7.4 Hz,1H), 7.67-7.23 (m, 29H), and the measured molecular weight of Compound 1by FAB-MS was 639 (C₄₈H₃₃NO).

(1-2-1-2. Synthesis of Compound 5)

According to the following Reaction 2, Compound 5 as the compoundrepresented by Formula 1 was synthesized. The product was identified bymeasuring the physical properties by ¹HNMR and FAB-MS.

(Synthesis of Compounds A and B)

Since the synthetic method of Compounds A and B are the same asdescribed above (1-2-1-1. Synthesis of Compound 1), explanationthereabout will not be provided again.

(Synthesis of Compound 5)

Under an Ar atmosphere, 3.10 g of Compound B, 1.28 g ofdibenzothiophene-4-boronic acid, 0.84 g of Pd(PPh₃)₄, and 2.35 g ofpotassium carbonate (K₂CO₃) were added to a 500 mL, three necked flask,followed by heating and stirring in a mixture solvent of 170 mL oftoluene and 80 mL of water at about 90° C. for about 8 hours. After aircooling, water was added to the reactant, an organic phase wasseparated, and solvents were distilled from the separated organic phase.The crude product thus obtained was separated by silica gel columnchromatography utilizing a mixture solvent of dichloromethane and hexaneand recrystallized utilizing a mixture solvent of toluene and hexane toproduce 2.94 g (Yield 80%) of Compound 5 as a white solid. Chemicalshift values (δ) of Compound 5 by ¹HNMR (300 MHz, CDCl₃) were 8.46-8.41(m, 2H), 8.20 (d, 1H, J=7.80 Hz), 7.98 (d, 1H, J=7.90 Hz), 7.58-7.50 (m,18H), 7.48-7.41 (m, 4H), 6.69-6.65 (m, 4H), and the measured molecularweight of Compound 5 by FAB-MS was 656 (C₄₈H₃₃NS).

(1-2-2. Manufacture of Organic EL Device Including Anode-Side HoleTransport Material and Anode-Side Hole Transport Layer Doped withElectron Accepting Material)

An organic EL device according to an embodiment was manufactured by thefollowing manufacturing method.

First, with respect to an ITO-glass substrate patterned and washed inadvance, surface treatment utilizing UV-Ozone (O₃) was conducted. Thelayer thickness of an ITO layer (first electrode) on a glass substratewas about 150 nm. After ozone treatment, the surface treated substratewas inserted in a glass bell jar evaporator for forming an organiclayer, and an anode-side hole transport layer, an intermediate holetransport material layer, an emission layer-side hole transport layer,an emission layer and an electron transport layer were evaporated one byone with a vacuum degree of about 10⁻⁴ to about 10⁻⁵ Pa. The layerthickness of each of the anode-side hole transport layer, theintermediate hole transport material layer and the emission layer-sidehole transport layer was about 10 nm. The layer thickness of theemission layer was about 25 nm, and the layer thickness of the electrontransport layer was about 25 nm. Then, the substrate was moved into aglass bell jar evaporator for forming a metal layer, and an electroninjection layer and a second electrode were evaporated with a vacuumdegree of about 10⁻⁴ to about 10⁻⁵ Pa. The layer thickness of theelectron injection layer was about 1 nm and the layer thickness of thesecond electrode was about 100 nm.

Here, the anode-side hole transport layer, the intermediate holetransport material layer and the emission layer-side hole transportlayer correspond to the hole transport layer with a stacked structure.The anode-side hole transport layer, the intermediate hole transportmaterial layer and the emission layer-side hole transport layer weremanufactured in examples and comparative examples utilizing thematerials shown in the following Table 1.

In Table 1, for example, the expression of “Compound 2-3, Compound 4-15”indicates that Compound 2-3 is the anode-side hole transport material,and Compound 4-15 is the doped electron accepting material. The amountdoped of the electron accepting material was about 3 wt % on the basisof the amount of the anode-side hole transport material.

In addition, Compounds 6-1, 6-2 and 6-3 refers to common hole transportmaterials represented by the following formula 12.

9,10-di(1-2-naphthyl)anthracene (ADN, Compound 3-2) was utilized as thehost material of the emission layer, and 2,5,8,11-tetra-t-butylperylene(TBP) was utilized as the dopant material. 3 wt % of the dopant materialon the basis of the amount of the host material was added. In addition,the electron transport layer was formed utilizing Alq3, the electroninjection layer was formed utilizing LiF, and the second electrode wasformed utilizing aluminum (Al).

(1-2-2. Evaluation Results)

Then, the driving voltage and the half life of the organic EL devicethus manufactured were evaluated. Evaluation results are shown togetherin the following Table 1. The driving voltage and the emissionefficiency in each example and comparative example were obtained bymeasuring at current density of about 10 mA/cm². The emission life wasobtained by measuring a time period for decreasing luminance to halfwith the initial luminance of about 1,000 cd/m².

In addition, the measurement was conducted utilizing a source meter of2400 series of Keithley Instruments Co., a Color brightness photometerCS-200 (Konica Minolta holdings Co., Ltd., measurement angle of 1°), anda PC program LabVIEW8.2 (National instruments Co., Ltd. in Japan) in adark room.

TABLE 1 Anode-side Intermediate hole hole Emission Driving Emissiontransport transport layer-side hole current efficiency Emission materialmaterial transport layer [V] [cd/A] life LT50 [h] Example CompoundCompound Compound 1 6.1 7.6 4,000 1-1 2-3, 2-3 Compound 4-15 ExampleCompound Compound Compound 5 6.1 7.5 4,100 1-2 2-3, 2-3 Compound 4-15Example Compound Compound Compound 1 6.2 7.4 3,900 1-3 2-3, 2-3 Compound4-16 Example Compound Compound Compound 1 6.1 7.6 3,200 1-4 2-3, 2-17Compound 4-15 Example Compound Compound Compound 1 6.5 7.5 3,200 1-56-2, 2-3 Compound 4-15 Example Compound Compound Compound 1 6.4 7.62,600 1-6 2-3, 6-3 Compound 4-15 Comparative Compound Compound 1Compound 2-3 6.4 7.2 2,100 Example 2-3, 1-1 Compound 4-15 ComparativeCompound Compound2-3 Compound 1 7.5 6.7 2,200 Example 2-3 1-2Comparative Compound Compound Compound 6-1 6.4 7.3 2,300 Example 2-3,2-3 1-3 Compound 4-15

Referring to Table 1, the emission efficiency was improved, and the halflife was increased for Examples 1-1 to 1-6 when compared to those forComparative Examples 1-1 to 1-3. Thus, the improvement of the emissionlife of the organic EL device could be realized by providing theanode-side hole transport layer, the intermediate hole transportmaterial layer and the emission layer-side hole transport layer betweenthe first electrode and the emission layer.

For example, if comparing Examples 1-1 to 1-6 with Comparative Example1-2, the properties for Examples 1-1 to 1-6 were better. In ComparativeExample 1-2, the electron accepting material (Compound 4-15 or 4-16) wasnot doped in the anode-side hole transport layer. Thus, it was found tobe desirable that the electron accepting material was doped in theanode-side hole transport layer.

If comparing Example 1-1 with Comparative Example 1-1, the propertiesfor Example 1-1 were better. In Comparative Example 1-1, compoundsincluded in the intermediate hole transport material layer and theemission layer-side hole transport layer were changed from those inExample 1-1. Thus, it was found to be desirable that the emissionlayer-side hole transport layer including the compound represented byFormula 1 was adjacent to the emission layer.

If comparing Example 1-1 with Comparative Example 1-3, the propertiesfor Examples 1-1 to 1-6 were better. In Comparative Example 1-3, theemission layer-side hole transport material included in the emissionlayer-side hole transport layer was not Compound 1 or 5 represented byFormula 1, but a common hole transport material, i.e., Compound 6-1.Thus, it was found to be desirable that the emission layer-side holetransport layer included the compound represented by Formula 1.

If comparing Examples 1-1 to 1-5 with Example 1-6, the properties forExamples 1-1 to 1-5 were better. In Example 1-6, the intermediate holetransport material included in the intermediate hole transport materiallayer was not Compound 2-3 or 2-17 represented by Formula 2 but a commonhole transport material, i.e., Compound 6-3. Thus, it was found to bedesirable that the intermediate hole transport material layer includedthe compound represented by Formula 2.

If comparing Examples 1-1 to 1-4 with Example 1-5, the properties ofExamples 1-1 to 1-4 were better. In Example 1-5, the anode-side holetransport material included in the anode-side hole transport layer wasnot Compound 2-3 represented by Formula 2 but a common hole transportmaterial, i.e., Compound 6-2. Thus, it was found to be desirable thatthe anode-side hole transport layer included the compound represented byFormula 2.

As described above, since the anode-side hole transport layer doped withthe electron accepting material, the intermediate hole transportmaterial layer, and the emission layer-side hole transport layerincluding the compound represented by Formula 1 were stacked between thefirst electrode (anode) and the emission layer, the emission efficiencyand emission life of the organic EL device were improved.

The results show that the hole transport layer may be passivated fromelectrons not consumed in the emission layer-side hole transport layer,the diffusion of energy in an excited state generated from the emissionlayer into the hole transport layer may be reduced or prevented, and thecharge balance of a whole device may be controlled by disposing theemission layer-side hole transport layer including the compoundrepresented by Formula 1. The results also show that the emissionlayer-side hole transport layer may restrain (e.g., reduce or prevent)the diffusion of the electron accepting material included in theanode-side hole transport layer provided near the first electrode(anode) into the emission layer by disposing the emission layer-sidehole transport layer including the compound represented by Formula 1.

<2-1. Configuration of Organic EL Device Including Anode-Side HoleTransport Layer Mainly Including Electron Accepting Material>

Hereinafter, an organic EL device including an anode-side hole transportlayer mainly including an electron accepting material will be explainedreferring to the drawing.

The organic EL device including the anode-side hole transport layermainly including the electron accepting material includes theabove-mentioned anode-side hole transport material and has substantiallythe same configuration, i.e., substantially the same configuration of asubstrate, substantially the same configuration of a first electrode,substantially the same configuration of an emission layer, substantiallythe same configuration of an electron transport layer, substantially thesame configuration of an electron injection layer, substantially thesame configuration of a second electrode and substantially the samemethod of manufacturing an organic EL device as those of the organic ELdevice including the anode-side hole transport layer doped with theelectron accepting material, and has a different configuration of thehole transport layer. Thus, the configuration of the hole transportlayer will be explained in more detail, hereinafter.

(2-1-1. Configuration of Hole Transport Layer)

The hole transport layer 130 may include a hole transport material andhave hole transporting function. The hole transport layer 130 may beformed, for example, on the first electrode 120 to a layer thickness(total layer thickness of a multi-layer structure) within a range fromabout 10 nm to about 150 nm.

Here, the hole transport layer 130 of the organic EL device 100according to an embodiment may be formed as a multi-layer by stackingfrom a first electrode 120, an anode-side hole transport layer 131, anintermediate hole transport material layer 133 and an emissionlayer-side hole transport layer 135 one by one. In addition, the ratioof the thicknesses of the layers is not specifically limited.

(2-1-1-1. Configuration of Anode-Side Hole Transport Layer)

The anode-side hole transport layer 131 may be a layer mainly includingan electron accepting material. For example, the anode-side holetransport layer 131 may be formed on the first electrode 120.

The anode-side hole transport layer 131 is a layer formed mainlyutilizing the electron accepting material, however, a material otherthan the electron accepting material may be included. In addition, theexpression that “the anode-side hole transport layer 131 may be formedmainly utilizing the electron accepting material” refers to that theanode-side hole transport layer 131 includes about 50 wt % or greater ofthe electron accepting material on the basis of the total amount of theanode-side hole transport layer 131.

The anode-side hole transport layer 131 may be formed mainly utilizingthe electron accepting material and may improve hole injection propertyfrom the first electrode 120. Thus, in one embodiment, the anode-sidehole transport layer 131 may be provided near the first electrode 120,and for example, the anode-side hole transport layer 131 may be providedadjacent to the first electrode 120.

The electron accepting material included in the anode-side holetransport layer 131 may be any suitable electron accepting materials.However, in one embodiment, the electron accepting material included inthe anode-side hole transport layer 131 may have a LUMO level within arange from about −9.0 eV to about −4.0 eV, and for example, the electronaccepting material included in the anode-side hole transport layer 131may have the LUMO level within a range from about −6.0 eV to about −4.0eV.

Here, examples of the electron accepting material having the LUMO levelwithin a range from about −9.0 eV to about −4.0 eV may include thecompounds represented by the following Formulae 4-1 to 4-14.

In the above Formulae 4-1 to 4-14, R is hydrogen, deuterium, a halogenatom, a fluoroalkyl group having 1 to 50 carbon atoms, a cyano group, analkoxy group having 1 to 50 carbon atoms, an alkyl group having 1 to 50carbon atoms, an aryl group having 6 to 50 carbon atoms or a heteroarylgroup having 5 to 50 carbon atoms for forming a ring. Ar is asubstituted aryl group with an electron withdrawing group or anunsubstituted aryl group having 6 to 50 carbon atoms for forming a ring,or a substituted or unsubstituted heteroaryl group having 5 to 50 carbonatoms for forming a ring; Y is a methine group (—CH═) or a nitrogen atom(—N═); Z is a pseudohalogen atom or a sulfur (S) atom; n is an integerof 10 and less; and X is one of the substituents represented by thefollowing formulae X1 to X7.

In the above Formulae X1 to X7, Ra is hydrogen, deuterium, a halogenatom, a fluoroalkyl group having 1 to 50 carbon atoms, a cyano group, analkoxy group having 1 to 50 carbon atoms, an alkyl group having 1 to 50carbon atoms, a substituted or unsubstituted aryl group having 6 to 50carbon atoms for forming a ring or a substituted or unsubstitutedheteroaryl group having 5 to 50 carbon atoms for forming a ring.

Examples of the substituted or unsubstituted aryl group having 6 to 50carbon atoms for forming a ring represented by R, Ar and Ra may includea phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthrylgroup, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a9-phenanthryl group, a 1-naphthacenyl group, a 2-naphthacenyl group, a9-naphthacenyl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenylgroup, a 2-biphenylyl group, a 3-biphenylyl group, a 4-biphenylyl group,a p-terphenyl-4-yl group, a p-terphenyl-3-yl group, a p-terphenyl-2-ylgroup, an m-terphenyl-4-yl group, an m-terphenyl-3-yl group, anm-terphenyl-2-yl group, an o-tolyl group, an m-tolyl group, a p-tolylgroup, a p-t-butylphenyl group, a p-(2-phenylpropyl)phenyl group, a3-methyl-2-naphthyl group, a 4-methyl-1-naphthyl group, a4-methyl-1-anthryl group, a 4′-methylbiphenylyl group, a4″-t-butyl-p-terphenyl-4-yl group, a fluoranthenyl group, a fluorenylgroup, etc.

Examples of the substituted or unsubstituted heteroaryl group having 5to 50 carbon atoms for forming a ring represented by R, Ar and Ra mayinclude a 1-pyrrolyl group, a 2-pyrrolyl group, a 3-pyrrolyl group, apyridinyl group, a 2-pyridinyl group, a 3-pyridinyl group, a 4-pyridinylgroup, a 1-indolyl group, a 2-indolyl group, a 3-indolyl group, a4-indolyl group, a 5-indolyl group, a 6-indolyl group, a 7-indolylgroup, a 1-isoindolyl group, a 2-isoindolyl group, a 3-isoindolyl group,a 4-isoindolyl group, a 5-isoindolyl group, a 6-isoindolyl group, a7-isoindolyl group, a 2-furyl group, a 3-furyl group, a 2-benzofuranylgroup, a 3-benzofuranyl group, a 4-benzofuranyl group, a 5-benzofuranylgroup, a 6-benzofuranyl group, a 7-benzofuranyl group, a1-isobenzofuranyl group, a 3-isobenzofuranyl group, a 4-isobenzofuranylgroup, a 5-isobenzofuranyl group, a 6-isobenzofuranyl group, a7-isobenzofuranyl group, a quinolyl group, a 3-quinolyl group, a4-quinolyl group, a 5-quinolyl group, a 6-quinolyl group, a 7-quinolylgroup, an 8-quinolyl group, a 1-isoquinolyl group, a 3-isoquinolylgroup, a 4-isoquinolyl group, a 5-isoquinolyl group, a 6-isoquinolylgroup, a 7-isoquinolyl group, an 8-isoquinolyl group, a 2-quinoxalinylgroup, a 5-quinoxalinyl group, a 6-quinoxalinyl group, a 1-carbazolylgroup, a 2-carbazolyl group, a 3-carbazolyl group, a 4-carbazolyl group,a 9-carbazolyl group, a 1-phenanthridinyl group, a 2-phenanthridinylgroup, a 3-phenanthridinyl group, a 4-phenanthridinyl group, a6-phenanthridinyl group, a 7-phenanthridinyl group, an 8-phenanthridinylgroup, a 9-phenanthridinyl group, a 10-phenanthridinyl group, a1-acridinyl group, a 2-acridinyl group, a 3-acridinyl group, a4-acridinyl group, a 9-acridinyl group, a 1,7-phenanthroline-2-yl group,a 1,7-phenanthroline-3-yl group, a 1,7-phenanthroline-4-yl group, a1,7-phenanthroline-5-yl group, a 1,7-phenanthroline-6-yl group, a1,7-phenanthroline-8-yl group, a 1,7-phenanthroline-9-yl group, a1,7-phenanthroline-10-yl group, a 1,8-phenanthroline-2-yl group, a1,8-phenanthroline-3-yl group, a 1,8-phenanthroline-4-yl group, a1,8-phenanthroline-5-yl group, a 1,8-phenanthroline-6-yl group, a1,8-phenanthroline-7-yl group, a 1,8-phenanthroline-9-yl group, a1,8phenanthroline-10-yl group, a 1,9-phenanthroline-2-yl group, a1,9-phenanthroline-3-yl group, a 1,9-phenanthroline-4-yl group, a1,9-phenanthroline-5-yl group, a 1,9phenanthroline-6-yl group, a1,9-phenanthroline-7-yl group, a 1,9-phenanthroline-8-yl group, a1,9-phenanthroline-10-ylgroup, a 1,10-phenanthroline-2-yl group, a1,10-phenanthroline-3-yl group, a 1,10-phenanthroline-4-yl group, a1,10-phenanthroline-5-yl group, a 2,9-phenanthroline-1-yl group, a2,9-phenanthroline-3-yl group, a 2,9-phenanthroline-4-yl group, a2,9-phenanthroline-5-yl group, a 2,9-phenanthroline-6-yl group, a2,9-phenanthroline-7-yl group, a 2,9-phenanthroline-8-yl group, a2,9-phenanthroline-10-yl group, a 2,8-phenanthroline-1-yl group, a2,8-phenanthroline-3-yl group, a 2,8-phenanthroline-4-yl group, a2,8-phenanthroline-5-yl group, a 2,8-phenanthroline-6-yl group, a 2,8-phenanthroline-7-yl group, a 2,8-phenanthroline-9-yl group, a2,8-phenanthroline-10-yl group, a 2,7-phenanthroline-1-yl group, a2,7-phenanthroline-3-yl group, a 2,7-phenanthroline-4-yl group, a2,7-phenanthroline-5-yl group, a 2,7-phenanthroline-6-yl group, a2,7-phenanthroline-8-yl group, a 2,7-phenanthroline-9-yl group, a2,7-phenanthroline-l0-yl group, a 1-phenazinyl group, a 2-phenazinylgroup, a 1-phenothiazinyl group, a 2-phenothiazinyl group, a3-phenothiazinyl group, a 4-phenothiazinyl group, a 10-phenothiazinylgroup, a 1-phenoxaziny group, a 2-phenoxazinyl group, a 3-phenoxazinylgroup, a 4-phenoxazinyl group, a 10-phenoxazinyl group, a 2-oxazolylgroup, a 4-oxazolyl group, a 5-oxazolyl group, a 2-oxadiazolyl group, a5-oxadiazolyl group, a 3-furazanyl group, a 2-thienyl group, a 3-thienylgroup, a 2-methylpyrrole-1-yl group, a 2-methylpyrrole-3-yl group, a2-methylpyrrole-4-yl group, a 2-methylpyrrole-5-yl group, a3-methylpyrrole-1-yl group, a 3-methylpyrrole-2-yl group, a3-methylpyrrole-4-yl group, a 3-methylpyrrole-5-yl group, a2-t-butylpyrrole-4-yl group, a 3-(2-phenylpropyl)pyrrole-1-yl group, a2-methyl-1-indolylgroup, a 4-methyl-1-indolyl group, a2-methyl-3-indolyl group, a 4-methyl-3-indolyl group, a2-t-butyl-1-indolyl group, a 4-t-butyl-1-indolyl group, a2-t-butyl-3-indolyl group, a 4-t-butyl-3-indolyl group, etc.

Examples of the substituted or unsubstituted fluoroalkyl group having 1to 50 carbon atoms represented by R and Ra may include a perfluoroalkylgroup such as a trifluoromethyl group, a pentafluoroethyl group, aheptafluoropropyl group and a heptadecafluorooctane group, amonofluoromethyl group, a difluoromethyl group, a trifluoroethyl group,a tetrafluoropropyl group, an octafluoropentyl group, etc.

Examples of the substituted or unsubstituted alkyl group having 1 to 50carbon atoms represented by R and Ra may include a methyl group, anethyl group, a propyl group, an isopropyl group, an n-butyl group, ans-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, ann-hexyl group, an n-heptyl group, an n-octyl group, a hydroxymethylgroup, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a2-hydroxyisobutyl group, a 1,2-dihydroxyethyl group, a1,3-dihydroxyisopropyl group, a 2,3-dihydroxy-t-butyl group, a1,2,3-trihydroxypropyl group, a chloromethyl group, a 1-chloroethylgroup, a 2-chloroethyl group, a 2-chloroisobutyl group, a1,2-dichloroethyl group, a 1,3-dichloroisopropyl group, a2,3-dichloro-t-butyl group, a 1,2,3-trichloropropyl group, a bromomethylgroup, a 1-bromoethyl group, a 2-bromoethyl group, a 2-bromoisobutylgroup, a 1,2-dibromoethyl group, a 1,3-dibromoisopropyl group, a2,3-dibromo-t-butyl group, a 1,2,3-tribromopropyl group, an iodomethylgroup, a 1-iodoethyl group, a 2-iodoethyl group, a 2-iodoisobutyl group,a 1,2-diiodoethyl group, a 1,3-diiodoisopropyl group, a2,3-diiodo-t-butyl group, a 1,2,3-triiodopropyl group, an aminomethylgroup, a 1-aminoethyl group, a 2-aminoethyl group, a 2-aminoisobutylgroup, a 1,2-diaminoethyl group, a 1,3-diaminoisopropyl group, a2,3-diamino-t-butyl group, a 1,2,3-triaminopropyl group, a cyanomethylgroup, a 1-cyanoethyl group, a 2-cyanoethyl group, a 2-cyanoisobutylgroup, a 1,2-dicyanoethyl group, a 1,3-dicyanoisopropyl group, a2,3-dicyano-t-butyl group, a 1,2,3-tricyanopropyl group, a nitromethylgroup, a 1-nitroethyl group, a 2-nitroethyl group, a 2-nitroisobutylgroup, a 1,2-dinitroethyl group, a 1,3-dinitroisopropyl group, a2,3-dinitro-t-butyl group, a 1,2,3-trinitropropyl group, a cyclopropylgroup, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a4-methylcyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a1-norbornyl group, a 2-norbornyl group, etc.

The substituted or unsubstituted alkoxy group having 1 to 50 carbonatoms represented by R and Ra may be a group represented by —OY.Examples of Y may include a methyl group, an ethyl group, a propylgroup, an isopropyl group, an n-butyl group, an s-butyl group, anisobutyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, ann-heptyl group, an n-octyl group, a hydroxymethyl group, a1-hydroxyethyl group, a 2-hydroxyethyl group, a 2-hydroxyisobutyl group,a 1,2-dihydroxyethyl group, a 1,3-dihydroxyisopropyl group, a2,3-dihydroxy-t-butyl group, a 1,2,3-trihydroxypropyl group, achloromethyl group, a 1-chloroethyl group, a 2-chloroethyl group, a2-chloroisobutyl group, a 1,2-dichloroethyl group, a1,3-dichloroisopropyl group, a 2,3-dichloro-t-butyl group, a1,2,3-trichloropropyl group, a bromomethyl group, a 1-bromoethyl group,a 2-bromoethyl group, a 2-bromoisobutyl group, a 1,2-dibromoethyl group,a 1,3-dibromoisopropyl group, a 2,3-dibromo-t-butyl group, a1,2,3-tribromopropyl group, an iodomethyl group, a 1-iodoethyl group, a2-iodoethyl group, a 2-iodoisobutyl group, a 1,2-diiodoethyl group, a1,3-diiodoisopropyl group, a 2,3-diiodo-t-butyl group, a1,2,3-triiodopropyl group, an aminomethyl group, a 1-aminoethyl group, a2-aminoethyl group, a 2-aminoisobutyl group, a 1,2-diaminoethyl group, a1,3-diaminoisopropyl group, a 2,3-diamino-t-butyl group, a1,2,3-triaminopropyl group, a cyanomethyl group, a 1-cyanoethyl group, a2-cyanoethyl group, a 2-cyanoisobutyl group, a 1,2-dicyanoethyl group, a1,3-dicyanoisopropyl group, a 2,3-dicyano-t-butyl group, a1,2,3-tricyanopropyl group, a nitromethyl group, a 1-nitroethyl group, a2-nitroethyl group, a 2-nitroisobutyl group, a 1,2-dinitroethyl group, a1,3-dinitroisopropyl group, a 2,3-dinitro-t-butyl group, a1,2,3-trinitropropyl group, etc.

Examples of the halogen atom represented by R and Ra may includefluorine (F), chlorine (Cl), bromine (Br), iodine (I), etc.

Here, example compounds of the electron accepting material may includethe following Compounds 4-15 and 4-16. For example, the LUMO level ofCompound 4-15 may be about −4.40 eV, and the LUMO level of Compound 4-16may be about −5.20 eV. However, the electron accepting material is notlimited to the following Compounds 4-15 and 4-16.

(2-1-1-2. Configuration of Intermediate Hole Transport Material Layer)

The intermediate hole transport material layer 133 may include anintermediate hole transport material. The intermediate hole transportmaterial layer 133 may be formed, for example, on the anode-side holetransport layer 131.

The intermediate hole transport material included in the intermediatehole transport material layer 133 may be any suitable hole transportmaterials. Examples of the intermediate hole transport material includedin the intermediate hole transport material layer 133 may be TAPC, acarbazole derivative (such as N-phenyl carbazole or polyvinylcarbazole), TPD, TCTA, NPB, etc.

However, the intermediate hole transport material may be a compoundrepresented by the following Formula 2.

In Formula 2, Ar₇ to Ar₉ are each independently a substituted orunsubstituted aryl group having 6 to 50 carbon atoms for forming a ringor a substituted or unsubstituted heteroaryl group having 5 to 50 carbonatoms for forming a ring.

Ar₁₀ is hydrogen, deuterium, a halogen atom, a substituted orunsubstituted aryl group having 6 to 50 carbon atoms for forming a ring,a substituted or unsubstituted heteroaryl group having 5 to 50 carbonatoms for forming a ring or a substituted or unsubstituted alkyl grouphaving 1 to 50 carbon atoms.

L₄ is a direct linkage, a substituted or unsubstituted arylene grouphaving 6 to 18 carbon atoms for forming a ring or a substituted orunsubstituted heteroarylene group having 5 to 15 carbon atoms forforming a ring.

Examples of Ar₇ to Ar₉ may include a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, an anthryl group, a phenanthrylgroup, a fluorenyl group, an indenyl group, a pyrenyl group, anacetonaphthenyl group, a fluoranthenyl group, a triphenylenyl group, apyridyl group, a furanyl group, a pyranyl group, a thienyl group, aquinolyl group, an isoquinolyl group, a benzofuranyl group, abenzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolylgroup, a benzothiazolyl group, a quinoxalyl group, a pyrazolyl group, adibenzofuranyl group, a dibenzothienyl group, etc. In one embodiment,examples of Ar₇ to Ar₉ may include the phenyl group, the biphenyl group,the terphenyl group, the fluorenyl group, the carbazolyl group, thedibenzofuranyl group, etc.

Examples of Ar₁₀ may include a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, an anthryl group, a phenanthrylgroup, a fluorenyl group, an indenyl group, a pyrenyl group, anacetonaphthenyl group, a fluoranthenyl group, a triphenylenyl group, apyridyl group, a furanyl group, a pyranyl group, a thienyl group, aquinolyl group, an isoquinolyl group, a benzofuranyl group, abenzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolylgroup, a benzothiazolyl group, a quinoxalyl group, a pyrazolyl group, adibenzofuranyl group, a dibenzothienyl group, a methyl group, an ethylgroup, a propyl group, an isopropyl group, an n-butyl group, etc. In oneembodiment, examples of Ar₁₀ may include the phenyl group, the biphenylgroup, the terphenyl group, the fluorenyl group, the carbazolyl group,the dibenzofuranyl group, etc.

Examples of L₄ other than the direct linkage may include a phenylenegroup, a biphenylene group, a terphenylene group, a naphthalene group,an anthrylene group, a phenanthrylene group, a fluorenylene group, anindenylene group, a pyrenylene group, an acetonaphthenylene group, afluoranthenylene group, a triphenylenylene group, a pyridylene group, afuranylene group, a pyranylene group, a thienylene group, a quinolylenegroup, an isoquinolylene group, a benzofuranylene group, abenzothienylene group, an indolylene group, a carbazolylene group, abenzoxazolylene group, a benzothiazolylene group, a kinokisariren group,a benzoimidazolylene group, a pyrazolylene group, a dibenzofuranylenegroup, a dibenzothienylene group, etc. In one embodiment, L₄ may includethe direct linkage, the phenylene group, the biphenylene group, theterphenylene group, the fluorenylene group, the carbazolylene group orthe dibenzofuranylene group.

Examples of the compound represented by Formula 2 may include thefollowing Compounds 2-1 to 2-17. However, the compound represented byFormula 2 is not limited to the following Compounds 2-1 to 2-17.

The intermediate hole transport material layer 133 may include thecompound represented by the above Formula 2 as the intermediate holetransport material, and may improve the hole transporting property ofthe hole transport layer 130. Thus, the driving voltage of the organicEL device 100 may decrease, and the emission efficiency and emissionlife thereof may be increased.

(2-1-1-3. Configuration of Emission Layer-Side Hole Transport Layer)

The emission layer-side hole transport layer 135 may include a compoundrepresented by the following Formula 1. The emission layer-side holetransport layer 135 may be formed, for example, on the intermediate holetransport material layer 133, adjacent to the emission layer 140.

In Formula 1, Y is O or S, R₁ to R₆ are each independently hydrogen,deuterium, a halogen atom, a substituted or unsubstituted alkyl grouphaving 1 to 15 carbon atoms, a substituted or unsubstituted silyl group,a substituted or unsubstituted aryl group having 6 to 30 carbon atomsfor forming a ring, a substituted or unsubstituted heteroaryl grouphaving 1 to 30 carbon atoms for forming a ring, or a substituted orunsubstituted aryl group or heteroaryl group formed via condensation ofoptional adjacent substituents; Ar₁ and Ar₂ are each independently asubstituted or unsubstituted aryl group having 6 to 30 carbon atoms forforming a ring, or a substituted or unsubstituted heteroaryl grouphaving 1 to 30 carbon atoms for forming a ring; L₁ to L₃ are eachindependently a direct linkage, a substituted or unsubstituted alkylenegroup having 1 to 15 carbon atoms, a substituted or unsubstitutedaralkylene group having 7 to 30 carbon atoms, a substituted orunsubstituted arylene group having 6 to 30 carbon atoms for forming aring, a substituted or unsubstituted heteroarylene group having 1 to 30carbon atoms for forming a ring, or a substituted or unsubstituteddivalent silyl group; m is an integer from 0 to 3; and n is an integerfrom 0 to 4.

Examples of R₁ to R₆ may include hydrogen, deuterium, a halogen atom, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, ananthryl group, a phenanthryl group, a fluorenyl group, an indenyl group,a pyrenyl group, an acetonaphthenyl group, a fluoranthenyl group, atriphenylenyl group, a pyridyl group, a furanyl group, a pyranyl group,a thienyl group, a quinolyl group, an isoquinolyl group, a benzofuranylgroup, a benzothienyl group, an indolyl group, a carbazolyl group, abenzoxazolyl group, a benzothiazolyl group, a quinoxalyl group, apyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, amethyl group, an ethyl group, a propyl group, an isopropyl group, ann-butyl group, etc. In one embodiment, examples of R₁ and R₆ may includethe hydrogen atom, the halogen atom, the methyl group, the phenyl group,the biphenyl group, the fluorenyl group, the carbazolyl group, and thedibenzofuranyl group.

Examples of Ar₁ and Ar₂ may include a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, an anthryl group, a phenanthrylgroup, a fluorenyl group, an indenyl group, a pyrenyl group, anacetonaphthenyl group, a fluoranthenyl group, a triphenylenyl group, apyridyl group, a furanyl group, a pyranyl group, a thienyl group, aquinolyl group, an isoquinolyl group, a benzofuranyl group, abenzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolylgroup, a benzothiazolyl group, a quinoxalyl group, a pyrazolyl group, adibenzofuranyl group, a dibenzothienyl group, etc. In one embodiment,examples of Ar₁ and Ar₂ may include the phenyl group, the biphenylgroup, the terphenyl group, the fluorenyl group, the carbazolyl group,the dibenzofuranyl group, etc.

Examples of L₁ to L₃ other than the direct linkage may be a divalentsubstituent of the substituent illustrated in the above Ar₁ and Ar₂(e.g., examples of L₁ to L₃ other than the direct linkage may be acorresponding divalent group of the groups listed above for Ar₁ andAr₂). In one embodiment, examples of L₁ to L₃ other than the directlinkage may include the phenylene group, the naphthylene group, thebiphenylene group, the thienothiophenylene group and the pyridylenegroup. L₁ to L₃ may include the direct linkage, the phenylene group andthe biphenylene group.

Examples of the compound represented by Formula 1 may include thefollowing Compounds 1 to 48. However, the compound represented byFormula 1 is not limited to the following Compounds 1 to 48.

The emission layer-side hole transport layer 135 may include thecompound represented by the above Formula 1 as the emission layer-sidehole transport material and may passivate the hole transport layer 130from electrons not consumed in the emission layer 140. Since theemission layer-side hole transport layer 135 includes the compoundrepresented by Formula 1, the diffusion of energy in an excited stategenerated in the emission layer 140 to the hole transport layer 130 maybe reduced or prevented. Thus, according to this configuration, theemission layer-side hole transport layer 135 may improve the currentflow durability of the hole transport layer 130.

The emission layer-side hole transport layer 135 may be formed near theemission layer 140, and for example, may be formed adjacent to theemission layer 140 to effectively reduce or prevent the diffusion of theelectrons or the energy from the emission layer 140.

Since the emission layer-side hole transport layer 135 includes thecompound represented by Formula 1, the charge balance of the wholeorganic EL device 100 may be controlled, and the diffusion of theelectron accepting material included in the anode-side hole transportlayer 131 into the emission layer 140 may be restrained (e.g., reducedor prevented). Accordingly, the emission layer-side hole transport layer135 may improve the charge transport property of the whole holetransport layer 130.

Since the emission layer-side hole transport layer 135 includes thecompound represented by Formula 1, the charge transport property andcurrent flow durability of the hole transport layer 130 may be improved.Thus, the emission layer-side hole transport layer 135 may decrease thedriving voltage and improve the emission efficiency and emission life ofthe organic EL device 100.

As explained above, the hole transport layer 130 including theanode-side hole transport layer 131, the intermediate hole transportmaterial layer 133 and the emission layer-side hole transport layer 135may improve the current flow durability and hole transport property ofthe organic EL device 100. Thus, the driving voltage may decrease andthe emission efficiency and emission life of the organic EL device 100may be improved.

2-2. Examples

Hereinafter, organic EL devices according to example embodiments will beexplained by referring to examples and comparative examples. Thefollowing embodiments are only for illustration, and the organic ELdevices according to example embodiments are not limited thereto.

(2-2-1. Synthesis of Compound Represented by Formula 1)

First, a synthetic method of a compound represented by Formula 1 will beexplained referring to synthetic methods of Compounds 1 and 5. Thefollowing embodiments are only for illustration, and the syntheticmethods of the compound represented by Formula 1 are not limitedthereto.

(2-2-1-1. Synthesis of Compound 1)

According to the following Reaction 1, Compound 1 in the followingFormula 13, which is the compound represented by Formula 1 wassynthesized. The product thus obtained was identified by measuring thephysical properties thereof by means of ¹ HNMR and FAB-MS.

(Synthesis of Compound A)

Under an Ar atmosphere, 53.8 g ofN-[1,1′-biphenyl]-4-yl-N-(4-bromophenyl)-[1,1′-biphenyl]-4-amine, 6.46 gof Pd(dppf)Cl₂.CH₂Cl₂, 33.3 g of KOAc and 33.0 g ofbis(pinacolato)diboron were added to a 2 L flask, followed by degassingunder vacuum and stirring in a dioxane solvent at about 100° C. forabout 12 hours. Then, the solvent was distilled from the reactant,CH₂Cl₂ and water were added thereto, and an organic phase was separated.To the separated organic phase, magnesium sulfate (Mg₂SO₄) and activatedclay were added, filtering with suction was performed, and the solventwas distilled. The crude product thus obtained was separated by silicagel column chromatography utilizing a mixture solvent of dichloromethaneand hexane to produce 56.8 g (Yield 98%) of Compound A as a white solid(FAB-MS: C₃₆H₃₄BNO₂, measured value 523).

(Synthesis of Compound B)

Under an Ar atmosphere, 10.0 g of Compound A, 6.00 g of1-iodo-3-bromobenzene, 1.54 g of Pd(PPh₃)₄, and 5.25 g of potassiumcarbonate (K₂CO₃) were added to a 300 mL, three necked flask, followedby heating and stirring in a mixture solvent of 450 mL of toluene and 60mL of water at about 90° C. for about 8 hours. After air cooling, waterwas added to a mixture, an organic phase was separated, and the solventswere distilled from the separated organic phase. The crude product thusobtained was separated by silica gel column chromatography utilizing amixture solvent of dichloromethane and hexane and recrystallizedutilizing a mixture solvent of toluene and hexane to produce 9.29 g(Yield 88%) of Compound B as a white solid (FAB-MS: C₃₆H₂₆BrN, measuredvalue 551).

(Synthesis of Compound 1)

Under an Ar atmosphere, 3.10 g of Compound B, 1.2 g ofdibenzofuran-4-boronic acid, 0.84 g of Pd(PPh₃)₄, and 2.35 g ofpotassium carbonate (K₂CO₃) were added to a 500 mL, three necked flask,followed by heating and stirring in a mixture solvent of 170 mL oftoluene and 80 mL of water at about 90° C. for about 8 hours. After aircooling, water was added to the reactant, an organic phase wasseparated, and the solvents were distilled from the separated organicphase. The crude product thus obtained was separated by silica gelcolumn chromatography utilizing a mixture solvent of dichloromethane andhexane and recrystallized utilizing a mixture solvent of toluene andhexane to produce 3.08 g (Yield 86%) of Compound 1 as a white solid.Chemical shift values (δ) of Compound 1 by ¹HNMR (300 MHz, CDCl₃) were8.11 (s, 1H), 8.00 (d, J=7.6 Hz, 1H), 7.96 (d, J=7.6 Hz, 1H), 7.87 (d,J=7.4 Hz, 1H), 7.67-7.23 (m, 29H), and the measured molecular weight ofCompound 1 by FAB-MS was 639 (C₄₈H₃₃NO).

(2-2-1-2. Synthesis of Compound 5)

According to the following Reaction 2, Compound 5 as the compoundrepresented by Compound 1 was synthesized. The product was identified bymeasuring the physical properties thereof by ¹HNMR and FAB-MS.

(Synthesis of Compounds A and B)

Since the synthetic method of Compounds A and B are substantially thesame as that described above (2-2-1-1. Synthesis of Compound 1),explanation thereabout will not be repeated.

(Synthesis of Compound 5)

Under an Ar atmosphere, 3.10 g of Compound B, 1.28 g ofdibenzothiophene-4-boronic acid, 0.84 g of Pd(PPh₃)₄, and 2.35 g ofpotassium carbonate (K₂CO₃) were added to a 500 mL, three necked flask,followed by heating and stirring in a mixture solvent of 170 mL oftoluene and 80 mL of water at about 90° C. for about 8 hours. After aircooling, water was added to the reactant, an organic phase wasseparated, and solvents were distilled from the separated organic phase.The crude product thus obtained was separated by silica gel columnchromatography utilizing a mixture solvent of dichloromethane and hexaneand recrystallized utilizing a mixture solvent of toluene and hexane toproduce 2.94 g (Yield 80%) of Compound 5 as a white solid. Chemicalshift values (δ) of Compound 5 by ¹HNMR (300 MHz, CDCl₃) were 8.46-8.41(m, 2H), 8.20 (d, 1H, J=7.80 Hz), 7.98 (d, 1H, J=7.90 Hz), 7.58-7.50 (m,18H), 7.48-7.41 (m, 4H), 6.69-6.65 (m, 4H), and the measured molecularweight of Compound 5 by FAB-MS was 656 (C₄₈H₃₃NS).

(2-2-2. Manufacture of Organic EL Device Including Anode-Side HoleTransport Material Mainly Including Electron Accepting Material)

An organic EL device according to an embodiment was manufactured by thefollowing manufacturing method.

First, with respect to an ITO-glass substrate patterned and washed inadvance, surface treatment utilizing UV-Ozone (O₃) was conducted. Thelayer thickness of an ITO layer (first electrode) on a glass substratewas about 150 nm. After ozone treatment, the surface treated substratewas inserted in a glass bell jar type evaporator for forming an organiclayer, and an anode-side hole transport layer, an intermediate holetransport material layer, an emission layer-side hole transport layer,an emission layer and an electron transport layer were evaporated one byone with a vacuum degree of about 10⁻⁴ to about 10⁻⁵ Pa. The layerthickness of each of the anode-side hole transport layer, theintermediate hole transport material layer and the emission layer-sidehole transport layer was about 10 nm. The layer thickness of theemission layer was about 25 nm, and the layer thickness of the electrontransport layer was about 25 nm. Then, the substrate was moved into aglass bell jar evaporator for forming a metal layer, and the electroninjection layer and the second electrode were evaporated with a vacuumdegree of about 10⁻⁴ to about 10⁻⁵ Pa. The layer thickness of theelectron injection layer was about 1 nm and the layer thickness of thesecond electrode was about 100 nm.

Here, the anode-side hole transport layer, the intermediate holetransport material layer and the emission layer-side hole transportlayer correspond to the hole transport layer with a stacked structure.The anode-side hole transport layer, the intermediate hole transportmaterial layer and the emission layer-side hole transport layer weremanufactured in examples and comparative examples utilizing thematerials shown in the following Table 2.

In Table 2, Compounds 6-1 and 6-2 represented by the following formulaeare referred to as common hole transport materials.

As the host material of the emission layer,9,10-di(2-naphthyl)anthracene (ADN, Compound 3-2) was utilized, and as adopant material, 2,5,8,11-tetra-t-butylperylene (TBP) was utilized. 3 wt% of the dopant material on the basis of the amount of the host materialwas added. In addition, the electron transport layer was formedutilizing Alq3, the electron injection layer was formed utilizing LiF,and the second electrode was formed utilizing aluminum (Al).

(2-2-2. Evaluation Results)

Then, the driving voltage, emission efficiency and half life of theorganic EL device thus manufactured were evaluated. Evaluation resultsare shown together in the following Table 2. The driving voltage and theemission efficiency in each example and comparative example wereobtained by measuring at current density of about 10 mA/cm². Theemission life was obtained by measuring a time period for decreasingluminance to half from the initial luminance of about 1,000 cd/m².

The measurement was conducted utilizing a source meter of 2400 series ofKeithley Instruments Co., a Color brightness photometer CS-200 (KonicaMinolta holdings Co., Ltd., measurement angle of 1°), and a PC programLabVIEW8.2 (National instruments Co., Ltd. in Japan) in a dark room.

TABLE 2 Emission Anode-side Intermediate layer-side hole hole holeDriving Emission Life transport transport transport voltage efficiencyLT₅₀ layer material layer layer [V] [cd/A] (h) Example 2-1 CompoundCompound Compound 1 6.3 7.6 4,100 4-15 2-3 Example 2-2 Compound CompoundCompound 5 6.3 7.6 4,100 4-15 2-3 Example 2-3 Compound Compound Compound1 6.5 7.5 3,900 4-16 2-3 Example 2-4 Compound Compound Compound 1 6.37.6 3,800 4-15 2-17 Example 2-5 Compound Compound Compound 1 6.4 7.63,200 4-15 6-2 Comparative Compound Compound 1 Compound 6.8 7.3 2,100Example 2-1 4-15 2-3 Comparative Compound Compound Compound 1 7.9 6.92,100 Example 2-2 2-3 2-3 Comparative Compound Compound Compound 6.9 7.42,300 Example 2-3 4-15 2-3 6-1

Referring to Table 2, the driving voltage may decrease, the emissionefficiency may be improved, and the emission life may be increased forExamples 2-1 to 2-5 when compared to those for Comparative Examples 2-1to 2-3. Thus, it would be desirable that the emission life of theorganic EL device may be increased by providing the anode-side holetransport layer, the intermediate hole transport material layer and theemission layer-side hole transport layer between the first electrode andthe emission layer.

For example, if comparing Examples 2-1 to 2-5 with Comparative Example2-3, the properties for Examples 2-1 to 2-5 were better. In ComparativeExample 2-3, the emission layer-side hole transport material included inthe emission layer-side hole transport layer was not Compound 1 or 5represented by Formula 1, but a common hole transport material, i.e.,Compound 6-1. Thus, it would be desirable that the emission layer-sidehole transport layer included the compound represented by Formula 1.

If comparing Example 2-1 with Comparative Example 2-1, the propertiesfor Example 2-1 were better. In Comparative Example 2-1, compoundsincluded in the intermediate hole transport material layer and theemission layer-side hole transport layer were changed from thoseutilized in Example 2-1. Thus, it would be desirable that the emissionlayer-side hole transport layer including the compound represented byFormula 1 was adjacent to the emission layer.

If comparing Examples 2-1 to 2-5 with Comparative Example 2-2, theproperties for Examples 2-1 to 2-5 were better. In Comparative Example2-2, the anode-side hole transport layer did not include the electronaccepting material (Compound 4-15 or 4-16) but Compound 2-3 representedby Formula 2. Thus, it would be desirable that the anode-side holetransport layer was formed mainly utilizing the electron acceptingmaterial.

If comparing Examples 2-1 to 2-4 with Example 2-5, the properties forExamples 2-1 to 2-4 were better. In Example 2-5, the intermediate holetransport material included in the intermediate hole transport materiallayer was not Compound 2-3 to 2-17 represented by Formula 2 but a commonhole transport material, i.e., Compound 6-2. Thus, it would be desirablethat the intermediate hole transport material layer may include thecompound represented by Formula 2.

As described above, since an anode-side hole transport layer formedmainly utilizing an electron accepting material, an intermediate holetransport material layer and an emission layer-side hole transport layerincluding a compound represented by Formula 1 were stacked between afirst electrode (anode) and an emission layer according to anembodiment, the driving voltage of an organic EL device may decrease,and the emission efficiency and emission life thereof may be improved.

By disposing the emission layer-side hole transport layer including thecompound represented by Formula 1, the emission layer-side holetransport layer may passivate the hole transport layer from electronsnot consumed in the emission layer, the diffusion of energy in anexcited state generated in the emission layer into the hole transportmay be reduced or prevented, and the charge balance of a whole devicemay be controlled. In addition, the results show that the emissionlayer-side hole transport layer restrained (e.g., reduced or prevented)the diffusion of the electron accepting material included in theanode-side hole transport layer provided near the first electrode(anode) by disposing the emission layer-side hole transport layerincluding the compound represented by Formula 1.

As described above, an anode side hole transport layer, an intermediatehole transport material layer, and an emission layer side hole transportlayer are provided between an anode and an emission layer according tothe present disclosure, and the emission efficiency and emission life ofan organic EL device may be increased.

Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list. Further, the use of “may” whendescribing embodiments of the inventive concept refers to “one or moreembodiments of the inventive concept.” Also, the term “exemplary” isintended to refer to an example or illustration.

As used herein, the term “substantially,” “about,” and similar terms areused as terms of approximation and not as terms of degree, and areintended to account for the inherent deviations in measured orcalculated values that would be recognized by those of ordinary skill inthe art. Also, any numerical range recited herein is intended to includeall sub-ranges of the same numerical precision subsumed within therecited range. For example, a range of “1.0 to 10.0” is intended toinclude all subranges between (and including) the recited minimum valueof 1.0 and the recited maximum value of 10.0, that is, having a minimumvalue equal to or greater than 1.0 and a maximum value equal to or lessthan 10.0, such as, for example, 2.4 to 7.6. Any maximum numericallimitation recited herein is intended to include all lower numericallimitations subsumed therein and any minimum numerical limitationrecited in this specification is intended to include all highernumerical limitations subsumed therein. Accordingly, Applicant reservesthe right to amend this specification, including the claims, toexpressly recite any sub-range subsumed within the ranges expresslyrecited herein.

The above-disclosed subject matter is to be considered illustrative andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true spirit and scope of the present disclosure. Thus, to themaximum extent allowed by law, the scope of the present disclosure is tobe determined by the broadest permissible interpretation of thefollowing claims and their equivalents, and shall not be restricted orlimited by the foregoing detailed description.

What is claimed is:
 1. An organic electroluminescent (EL) device,comprising: an anode; an emission layer; and an hole transport layerbetween the anode and the emission layer; wherein the hole transportlayer comprises a hole transport material represented by Formula 1:

wherein in Formula 1, Y is O or S; R₁ to R₆ are each independentlyhydrogen, deuterium, a halogen atom, a substituted or unsubstitutedalkyl group having 1 to 15 carbon atoms, a substituted or unsubstitutedsilyl group, a substituted or unsubstituted aryl group having 6 to 30carbon atoms for forming a ring, a substituted or unsubstitutedheteroaryl group having 1 to 30 carbon atoms for forming a ring, or asubstituted or unsubstituted aryl group or heteroaryl group formed viacondensation of optional adjacent substituents; Ar₁ and Ar₂ are eachindependently a substituted or unsubstituted aryl group having 6 to 30carbon atoms for forming a ring, and each of Ar₁ and Ar₂ is not aheteroaryl-containing group; L₁ to L₃ are each independently a directlinkage, a substituted or unsubstituted alkylene group having 1 to 15carbon atoms, a substituted or unsubstituted aralkylene group having 7to 30 carbon atoms, a substituted or unsubstituted arylene group having6 to 30 carbon atoms for forming a ring, a substituted or unsubstitutedheteroarylene group having 1 to 30 carbon atoms for forming a ring, or asubstituted or unsubstituted divalent silyl group; m is an integer from0 to 3, and n is an integer from 0 to
 4. 2. The organic EL device ofclaim 1, wherein the hole transport layer comprises an anode-side holetransport layer between the anode and the emission layer; anintermediate hole transport material layer between the anode-side holetransport layer and the emission layer; and an emission layer-side holetransport layer between the intermediate hole transport material layerand the emission layer.
 3. The organic EL device of claim 2, wherein atleast one of the intermediate hole transport layer or the anode-sidehole transport layer comprises a compound represented by Formula 2:

wherein in Formula 2, A₇ to Ar₉ are each independently a substituted orunsubstituted aryl group having 6 to 50 carbon atoms for forming a ring,or a substituted or unsubstituted heteroaryl group having 5 to 50 carbonatoms for forming a ring; Ar₁₀ is hydrogen, deuterium, a halogen atom, asubstituted or unsubstituted aryl group having 6 to 50 carbon atoms forforming a ring, a substituted or unsubstituted heteroaryl group having 5to 50 carbon atoms for forming a ring, or a substituted or unsubstitutedalkyl group having 1 to 50 carbon atoms; and L₄ is a direct linkage, asubstituted or unsubstituted arylene group having 6 to 18 carbon atomsfor forming a ring, or a substituted or unsubstituted heteroarylenegroup having 5 to 15 carbon atoms for forming a ring.
 4. The organic ELdevice of claim 2, wherein the anode-side hole transport layer comprisesan anode-side hole transport material and doped with an electronaccepting material, and the electron accepting material has a lowestunoccupied molecular orbital (LUMO) level within a range from about −9.0eV to about −4.0 eV.
 5. The organic EL device of claim 2, wherein theanode-side hole transport layer comprising an electron acceptingmaterial as a main component, and the electron accepting material has alowest unoccupied molecular orbital (LUMO) level within a range fromabout −9.0 eV to about −4.0 eV
 6. The organic EL device of claim 1,wherein the emission layer comprises a compound represented by Formula3:

wherein in Formula 3, Ar₁₁ is each independently hydrogen, deuterium, asubstituted or unsubstituted alkyl group having 1 to 50 carbon atoms, asubstituted or unsubstituted cycloalkyl group having 3 to 50 carbonatoms for forming a ring, a substituted or unsubstituted alkoxy grouphaving 1 to 50 carbon atoms, a substituted or unsubstituted aralkylgroup having 7 to 50 carbon atoms, a substituted or unsubstitutedaryloxy group having 6 to 50 carbon atoms for forming a ring, asubstituted or unsubstituted arylthio group having 6 to 50 carbon atomsfor forming a ring, a substituted or unsubstituted alkoxycarbonyl grouphaving 2 to 50 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 50 carbon atoms for forming a ring, a substituted orunsubstituted heteroaryl group having 5 to 50 carbon atoms for forming aring, a substituted or unsubstituted silyl group, a carboxyl group, ahalogen atom, a cyano group, a nitro group, or a hydroxyl group; and ois an integer from 1 to 10.